• 24-Hour Urine Sample

    A collection of all urine voided over a 24-hour period of time.

    Obtain a collection container from your doctor or the laboratory and follow the directions you are given for collecting your samples. To preserve the substance to be tested, the container may need to be refrigerated during the entire collection process. After getting up in the morning, empty your bladder and discard that urine. Note the time. For the next 24 hours, save all urine voided in the container provided. When 24 hours are over, empty your bladder and ADD this urine to the container. Note the time. Bring all of the urine collected to the lab or doctor’s office. If you miss collecting one or more voids, consult your doctor or the laboratory for further instructions.

    The reason a 24-hour urine sample may be requested instead of a random urine sample is because amounts of various substances in the urine changes during the course of a day. By collecting all urine for 24 hours


  • Abnormal Fibrinolysis

    Overactivity of the process normally responsible for clearing blood clots from blood vessels

  • Abscess

    An enclosed localized collection of pus formed by the disintegration of tissue within a cavity

  • Acanthosis nigricans

    Darkening and thickening of the skin around the neck, underarms, and skin folds; can be caused by elevated levels of insulin in the blood and is often associated with obesity

  • Acid

    A compound that contains at least one hydrogen atom and can react with a base to form a salt; a chemical with a pH less than 7. An example of acid in the body is hydrochloric acid (HCl) involved in digestion in the stomach.

  • Acid-Base Balance

    The body’s maintenance of a healthy pH range for blood and tissues that is slightly basic (pH between 7.35 – 7.45). This balance is achieved through the use of systems in the blood (which help to minimize pH changes) and by the lungs and kidneys, which eliminate excess amounts of acids or bases from the body.

  • Acidosis

    A condition in which there is a shift in the acid-base balance of the body to have more acid than normal, often causing the pH of the blood and body tissues to fall below the healthy range (7.35-7.45). It may be caused by decreased CO2 eliimination in respiratory disorders such as emphysema, by metabolic problems such as kidney disease and diabetes, or as the result of ingesting poisons (ethlylene glycol, methanol) or overdosing on certain medication (salicylates); it can also be caused by losing HCO3, as in diarrhea.

  • Acromegaly

    A condition in adults resulting from excess growth hormone characterized by enlargement of the hands and feet, change in shoe size, gradual changes in facial features, including protrusion of the lower jaw and brow, and enlargement of the nasal bone

  • Acute

    1. A condition or illness that usually has a rapid onset of symptoms and may resolve within days with or without treatment. It is the opposite of chronic.
    2. A condition or illness that is sudden or severe.

  • Acute coronary syndrome (ACS)

    A group of potentially life-threatening disorders resulting from insufficient blood flow to the heart caused by the narrowing or blockage of one or more blood vessels to the heart; the conditions included in this group range from unstable angina to heart attack and are usually characterized by chest pain, upper body discomfort with pain in one or both arms, shoulders, stomach or jaw, shortness of breath, nausea, sweating or dizziness.

  • Acute Myelocytic Leukemia

    bone marrow disease that is characterized by the production of large numbers of an immature granulocyte (a neutrophil — the most common, basophil, or eosinophil) that replace other normal cells in the marrow.

  • Acute Phase Reactant

    A protein that increases or decreases in concentration with conditions that cause acute tissue inflammation or trauma.

  • Acute Sample

    In the clinical laboratory, pertaining to samples taken at a time when a patient initially exhibits signs and symptoms of a disease or condition

  • Adenomatous polyp

    Abnormal growth of cells that form the glands in the lining of the colon or rectum; while benign, may become cancerous over time

  • Adjuvant therapy

    Treatment used to assist a primary therapy (such as surgery) in the prevention, improvement, or cure of a disease (such as adjuvant chemotherapy in cancer)

  • Adrenal Gland

    One of a pair of glands located above each kidney that secretes hormones directly into the bloodstream. Each gland has two parts that perform different functions.

    1. The adrenal cortex produces and secretes hormones such as cortisol, aldosterone and sex steroids. They are involved in many different body functions.

    2. The adrenal medulla produces and secretes catecholamines such as adrenaline (epinephrine) and norepinephrine.

  • Aerobic

    Living or occurring in an oxygen-rich environment

  • Afibrinogenemia

    The absence of fibrinogen production

  • Alkalosis

    A condition in which a there is a shift in the acid-base balance of the body to have more base than normal, often causing the pH of the blood and body tissues to rise above the healthy range (7.35-7.45). It may have respiratory causes such as hyperventilation and pneumonia or metabolic causes such as prolonged vomiting and severe dehydration.

  • Allele

    Any one of the possible alternative forms in which a specific gene can occur

  • Allergen

    Substance (e.g., ragweed pollen) that can cause an allergy

  • Alopecia

    Loss of hair

  • Ambiguous genitalia

    Sex organs (genitals) that are not distinctly male or female in appearance. It is a condition present at birth (congenital) that results from a disruption in the formation of sex organs during fetal development.

  • Amenorrhea

    The absence or suppression of a woman’s monthly menstrual period.

  • Amino Acid

    One of a group of chemical compounds (organic acids) that have an amino group (NH2); many are the building blocks of proteins.

  • Amniotic fluid

    Fluid surrounding and supporting a fetus

  • Amplification

    1) In molecular diagnostics, a process by which multiple copies of genetic material (RNA, DNA) are generated so as to produce adequate levels of the target to be detected or quantitated

    2) The process by which the signal from a detection system is increased so as to improve detection or quantitation of an analyte of interest, such as genes or drugs

    3) When there is more than the normal number of copies of a gene or genes in a cell, as in tumor cells, the gene is said to be amplified.

  • Anaerobic

    Living or occurring in an oxygen-free environment

  • Analyte

    In the clinical laboratory, a substance from the body that is undergoing analysis.  In lay terms, often referred to as a test.””

  • Anaphylaxis

    Severe allergic reaction that can cause intensely itchy welts (hives) on the skin, low blood pressure, and difficulty breathing. Anaphylaxis can be life-threatening so those who have been affected by it may be advised to carry an emergency injection of epinephrine.

  • Androgens

    Hormones that are responsible for the induction of sexual differentiation and produce secondary male physical characteristics such as a deep voice and facial hair. An example is the hormone testosterone. They are also present in females as precursors to female hormones (such as estrogen).

  • Anencephaly

    Congenital defect that occurs during fetal brain development when the neural tube fails to close properly at the head. The result is the lack of development of a large portion of the brain and skull.

  • Aneuploidy

    Having an abnormal number of chromosomes

  • Aneurysm

    Weakened portion of a blood vessel wall that widens or bulges and may eventually rupture; a ruptured aneurysm can bleed heavily and may be fatal.

  • Angioedema

    An allergic reaction involving the skin and deeper (subcutaneous) layers that is characterized by patches of swelling

  • Angioplasty

    Medical procedure used to widen blood vessels that have been narrowed or blocked.  During the procedure, a balloon-tipped catheter is inserted into the body (usually through a small incision in the groin). The catheter is guided to the site of the blockage using X-rays and injected dye. The balloon on the catheter is then gently inflated to flatten the blockage and open the blood vessel.

  • Anovulation

    An egg is not released by the ovaries during a menstrual cycle 


  • Anterior

    At or toward the front

  • Antibiotic resistance

    Ability of a microorganism to grow despite the presence of an antibiotic

  • Antibody

    A protein produced by lymphoid tissue in response to the presence of an antigen.

  • Anticoagulant

    1. Drug that delays blood clotting (e.g., heparin, warfarin); used in patients with or at risk for blood clots
    2. Substance used to prevent clotting in blood used for transfusions and certain laboratory tests

  • Antigen

    1. Substance that causes the production of an antibody that binds to the antigen in order to damage, neutralize or kill it.

    2. The presence of certain antigens on blood cells is the basis for blood typing for transfusions. Antigens that are present on tissue allow for donor-recipient matching in transplant medicine.

  • Antihistamine

    A class of drugs that is used to treat allergies, hypersensitivity reactions, and the symptoms of colds. These drugs work by reducing the effects of histamine, a naturally-occurring substance that is released in response to inflammation and allergies.

  • Antimicrobial

    capable of killing or inhibiting the growth of a microbe, such as a virus, bacterium or fungus; an agent or drug that has this effect

  • Apheresis

    Process of removing a specific component from blood, such as platelets or white blood cells, and returning the remaining components to the donor; allows for more of one particular component to be collected than could be separated from a unit of whole blood

  • Apnea

    Short pauses or cessations in breathing

  • Apoprotein

    General term for a protein without its characteristic prosthetic group, which may be a metal or a small organic compound; for example, the protein apotransferrin combines with iron to form transferrin, and protein apoceruloplasmin combines with copper to form the enzyme ceruloplasmin.

  • Arrhythmia

    Changes in the rhythm of heartbeats or in the strength of heart contractions

  • Ascites

    Fluid buildup in the peritoneal (abdominal) cavity

  • Aspiration

    Use of suction to take liquids, gases, or cells from a body cavity or area, as in aspiration biopsy

  • Assay

    Procedure used to detect or measure a substance or reaction; test

  • Asymptomatic

    Without symptoms.

  • Atherosclerosis

    Common disorder of the arteries in which deposits consisting mostly of cholesterol and lipids form on the inner arterial wall. As a result, the vessels become nonelastic and narrowed, leading to decreased blood flow. One of the most important examples is coronary artery disease.

  • Atrial Fibrillation

    Condition characterized by an irregular, often rapid, heart rhythm

  • Auer Bodies

    unique, pink or red rod-shaped inclusions that are seen in very immature granulocytes (blasts”) in people with acute non-lymphocytic leukemia (i.e.

  • Autoimmunity

    Misdirected immunity with production of antibodies that act against the tissues of one’s own body

  • Autosome

    Any one of the 22 pair of chromosomes that do not determine sex; only the X and Y chromosomes determine sex.


  • Bacteremia

    Presence of bacteria in the blood

  • Bacterium

    Plural: Bacteria

    Unicellular microscopic organisms, some of which cause disease

  • Base

    1) Substance that has a hydroxyl (OH) ion, tastes bitter, has a pH greater than 7 and, when combined with an acid, forms a salt; example of a base is ammonia

    2) One of the building blocks of DNA and RNA

  • Basophil

    Type of white blood cell (leukocyte), with coarse granules that stain blue when exposed to a basic dye. Basophils normally constitute 1% or less of the total white blood cell count but may increase or decrease in certain diseases.

  • Bence Jones protein

    A protein that may be found in the urine of people with certain forms of protein disorders, such as amyloidosis and multiple myeloma. In most cases of multiple myeloma, a single type of intact (whole) immunoglobulin is produced in excess. In a minority of cases, only one section of an immunoglobulin called a free light chain” is produced in large amounts. These excess free light chains are released into the bloodstream and since they are relatively small molecules

  • Benign

    1. Mild, non-cancerous, and/or not spreading (compare Malignant)

  • Beta Blockers

    A group of drugs that blocks the effect of adrenaline, slows the heart rate, and decreases the strength of the heart’s contractions and thereby lowers blood pressure and relieves symptoms of angina and arrhythmias

  • Beta Cells

    Specialized cells in the pancreas that produce and secrete insulin

  • Bile

    Thick, yellow-green-brown fluid made by the liver, stored in the gallbladder, and discharged into the upper part of the digestive tract (duodenum), where it dissolves fats, preparing them for further digestion.

  • Biliary

    Pertaining to bile or the ducts of the liver and gall blader

  • Biomarker

    A substance produced by the body, often detectable in body fluids such as blood or urine, that indicates a specific process, condition or disease

  • Biopsy

    Removal of a small amount of tissue and/or fluid; the specimen is usually obtained by cutting or by suction through a needle.

  • Bite cells

    Abnormally-shaped red blood cells with one or more semicircular portions removed from the cell margin, appearing as though the cells have had bite” or “bites.” The “bites” result from the removal of hemoglobin with an altered structure (denatured) by special cells (macrophages) in the spleen. G6PD deficiency is a common disorder that leads to the formation of bite cells

  • Blast

    Immature or primitive cell; precursor cell

  • Boil

    A painful, inflamed area of skin with a defined border, collection of pus and a hard central core usually caused by a bacterial infection of a hair follicle and surrounding tissue

  • Bone Marrow

    Specialized soft tissue found within bone. Red bone marrow, widespread in the bones of children and found in some adult bones (e.g., pelvis, spine, ribs), is essential for the formation of mature red blood cells. Fat-laden yellow bone marrow, more common in adults, is found primarily at the ends of long bones.

  • Breakpoint

    In genetics, the particular sites of disruption when chromosomes break (and recombine)

  • Brittle diabetes

    Describes diabetes that is difficult to control, with frequent swings in blood glucose levels between very high and very low

  • Broad-spectrum Antibiotic Therapy

    Treatment with one or more drugs that is effective against a wide variety of bacteria

  • Bronchiectasis

    A condition in which the airways are stretched and/or widened that can be caused by recurrent inflammation or infection of the airways and results in symptoms such as bluish skin, coughing and wheezing, and shortness of breath

  • Bronchioles

    The smaller airway passages/branches of the lower respiratory tract

  • Bronchiolitis

    Inflamed bronchioles, the smaller airway passages/branches of the lower respiratory tract

  • Bronchodilator

    Drug that dilates (opens) the bronchi, muscular tubes that carry air throughout the lungs

  • Bronchus

    One of the two main branches of the windpipe (trachea) that lead directly to the lungs


  • Calcification

    Hardening of tissue resulting from the formation of calcium salts

  • Calibrate

    To adjust the output or reading from a testing device to assure that it gives a correct answer; the adjustment is based on measurement of one or more known substances called standards (or calibrators).

  • Capillary

    The tiniest of blood vessels. Through the one-cell-layer-thick walls of capillaries, oxygen and nutrients are delivered to body tissues and carbon dioxide and other wastes are cleared from body tissues.

  • Carbohydrate

    The starches and sugars that are the chief energy sources of the body

  • Carbuncle

    A collection of boils caused by an infection of a large area of skin involving several hair follicles and deeper layers of tissue; the area often has several openings for pus drainage and sloughing dead tissue

  • Carcinoid tumor

    Slow-growing mass that can develop in the mucous membrane of the gastrointestinal (GI) tract and sometimes the lungs

  • Cardiac calcium score

    A computed tomography (CT) scan of the arteries leading to the heart. The scan provides images of calcium deposits that can narrow or block the arteries. The higher the cardiac calcium score, the more likely the patient has heart disease or will be at higher risk for heart attack.

  • Cardiovascular System

    The heart and blood vessels involved in the pumping of blood and the transport of nutrients, oxygen, and waste products throughout the body

  • Carrier

    1. Person, generally in apparent good health, who harbours organisms that can infect and cause disease in others

    2. Person who has one copy of a recessive disease gene but is not affected themselves

  • Cartilage

    Tissue that lines joints to absorb shock; it also forms the shape of the nose and ears.

  • Catheter

    1. long, thin, flexible tube inserted into a body cavity or vessel to allow the passage of fluids
    2. thin, flexible tube inserted into a vessel in the body for the purpose of opening (distending) the vessel

  • Central Nervous System (CNS)

    One of the two main divisions of the human nervous system, consisting of the brain and the spinal cord; the other division is the peripheral nervous system.

  • Centrifugation

    The automated process of separating lighter portions of a solution, mixture, or suspension from the heavier portions, by centrifugal force

  • Cerebrospinal Fluid (CSF)

    Normally clear liquid, produced in the ventricles of the brain, that surrounds the brain and spinal cord

  • Cervical Adenitis

    Lymph node inflammation in the neck

  • Chain of Custody

    Legal document created when a piece of evidence is obtained that records the movement, location, handling and/or testing of the evidence from the time it is collected until the evidence is used in a legal proceeding and/or until it is no longer needed and is discarded or destroyed

  • Chelation

    Binding of a metal ion by a large molecule to form a soluble complex; chelation therapy uses large molecules such as EDTA (ethylene diamine tetraacetic acid) to remove excess metals (like lead or iron) from tissues and enable their excretion.

  • Chemotherapy

    In the treatment of cancer, the use of medicines or drugs to stop or slow the growth of cancer cells; because chemo can also harm healthy cells, it can be associated with side effects, such as fatigue, hair loss, mouth sores, and nausea/vomiting.

  • Chloroquine

    Drug used in the treatment and prevention of malaria

  • Chorionic villus sampling (CVS)

    This test is not routinely performed but may be discussed with or offered to pregnant women who are at an increased risk of having a baby with certain chromosome disorders

  • Chromosome

    Threadlike structure in every cell nucleus that carries the inheritance factors (genes) composed of DNA (deoxyribonucleic acid, the gene material) and a protein (usually histone). A human cell normally contains 46 chromosomes, or 22 homologous pairs and 1 pair of sex chromosomes; one member of each pair of chromosomes is derived from each parent.

  • Chronic

    A condition or illness that arises slowly over days or weeks and may or may not resolve with treatment. It is the opposite of acute.

  • Clone

    (noun) Cell, group of cells, or organisms that descend from a single cell or organism; clones are genetically identical

    (verb) To replicate or produce identical copies

  • Cognitive

    (n. cognition) Relating to the mental process of acquiring knowledge through awareness, perception, intuition, and reasoning

  • Collagen

    A group of proteins that form elongated fibers that are the main component in connective tissues such as skin, ligaments, tendons, cartilage and bone

  • Colonization

    The presence or growth of bacteria on or in the body; those who are colonized may or may not develop an infection and/or may spread the bacteria to others, in whom they may cause disease.

  • Colonoscopy

    Examination of the rectum and entire colon with a flexible lighted instrument

  • Colposcopy

    a procedure in which a health practitioner uses a lighted magnifying instrument to examine a woman’s cervix for abnormal areas, to take samples for biopsy, and/or treat as indicated

  • Congenital

    Present at birth

  • Conjugated bilirubin

    A water-soluble form of bilirubin formed in the liver by the chemical addition of sugar molecules to unconjugated bilirubin; when present in the blood, conjugated bilirubin can become chemically bound to albumin, forming delta-bilirubin (also known as biliprotein).

  • Connective tissue

    Tissue that connects organs or other structures within the body. It supports, attaches and encloses organs, fills the spaces between them, and forms ligaments and tendons.

  • Convalescent Sample

    In the clinical laboratory, pertaining to samples taken at a time when a patient is recovering from a disease or condition

  • Corpus Luteum

    Literally, yellow body in the ovary; the progesterone-producing tissue that remains after an egg is releaed from the ovary

  • Creatine Kinase (CK)
    No definition
  • Cryoprecipitate

    A component prepared from donated blood; after freezing plasma and thawing, a precipitate that remains solid. It is rich in fibrinogen and Factor VIII.

  • Culture

    Deliberate growing of cells, especially microorganisms, in a solid or liquid medium (e.g. agar, gelatin), as of bacteria in a Petri dish

  • Cyst

    1) a hollow space or fluid-filled cavity surrounded by a distinct lining that develops abnormally in tissue or in an organ in the body, such as “ovarian cyst

    2) a cellular form of a parasite that has a thick cell wall, which allows for survival of the parasite in the environment and transmission into an uninfected host

  • Cytokine

    one of a group of proteins released by cells of the immune system that carry signals to neighboring cells to regulate and/or promote an immune response

  • Cytology

    The microscopic assessment of individual cells or groups of cells that are either shed in body fluids or collected by smears and scrapings (e.g., the Pap smear) or by aspiration from deeper tissues through a very fine needle

  • Cytoplasm

    The living substance within a cell that is located outside of the nucleus; it is a semi-fluid substance consisting of proteins, fat and other molecules


  • Dementia

    Progressive state of mental decline, especially of memory function and judgment

  • Dermatitis

    Acute or chronic inflammation of the skin

  • Dermatophyte

    Any one of the group of fungi that cause infection of the skin, hair, or nails

  • Diabetes insipidus

    A disorder similar to diabetes mellitus in that it causes symptoms such as increased thirst and increased urine production

  • Differentiate

    Change from an original unspecialized form, to a different more specialized form or function.

  • Digital Rectal Exam (DRE)

    Part of a physical examination performed in order to examine nearby structures (e.g., the prostate in men)

  • Diuretic

    Drug that promotes the production and excretion of urine in order to remove excess fluid from the body in, for example, conditions such as congestive heart failure or hypertension

  • Diverticulosis

    A condition characterized by having pouches (diverticulum) that poke through parts of the colon

  • DNA (deoxyribonucleic acid)

    The unique genetic code found in all living cells (bacteria, viruses, parasites, plants, and animals).

  • Dominant gene

    One of a pair of genes whose action is expressed even when only one copy is present

  • Doping

    The use of substances or procedures to improve athletic performance and give an athlete an unfair advantage over other competitors.

  • Double contrast barium enema

    Series of x-rays of the colon and rectum; patient is given an enema with a white, chalky solution that outlines the colon and rectum on the x-rays.

  • Dumping syndrome

    Symptoms such as nausea, cramping, sweating, and weakness that may occur when the stomach contents are emptied rapidly into the small intestine before being digested; may occur in patients who have had gastric resections or bypass surgery

  • Duodenum

    first part of the small intestine that receives digesting material from the stomach

  • Dysfibrinogenemia

    The production of abnormal fibrinogen

  • Dyslipidemia

    Unhealthy lipid levels

  • Dyspnea

    Shortness of breath; labored breathing

  • Dystonia

    Persistent muscle contractions that can cause limb twisting and repetitive motions


  • E. coli

    A species of bacteria that normally resides in the gastrointestinal tract as harmless normal flora; these rod-shaped bacteria commonly cause urinary tract infections, and some strains produce toxins that cause diarrheal disease.

  • Echocardiography

    Diagnostic procedure using ultrasound waves to study the heart, its structure and motions; images from this procedure are called echocardiograms.

  • Eclampsia

    Coma and convulsive seizures that occur at or after the 20th week of pregnancy. Associated with pregnancy-induced hypertension, it can be fatal if untreated.

  • Ectopic Pregnancy

    Abnormal pregnancy in which the fertilized egg implants outside of the uterus, most often (90%) in the fallopian tube (tubal pregnancy)

  • Eczema

    Skin condition characterized by red, itchy, scaly and sometimes blistering patches

  • Edema

    Abnormal collection of fluid in spaces between cells, esp. just under the skin or in a given cavity (e.g., peritoneal cavity) or organ (e.g., the lungs-pulmonary edema)

  • Effusion

    Escape of fluid from blood vessels or lymphatic system into a body cavity or space

  • Electrocardiogram

    Graphic recording of the electrical activity of the heart

  • Embolism & Thromboembolism

    Embolism— a condition in which material (tissue, fat, air, blood clot, etc.—called an embolus) travels through the bloodstream and then becomes lodged in a vein or artery and blocks the flow of blood through that blood vessel.

    Thromboembolism—a blood clot (thrombus) that breaks free in the blood stream and blocks a blood vessel. This can occur in a vein (venous thromboembolism) or in an artery (arterial thromboembolism).

  • Emphysema

    Chronic progressive lung disease in which air sacs (alveoli) in the lungs are damaged, resulting in loss of elasticity and function of the lungs; the condition is characterized by shortness of breath and may be accompanied by a cough.  It may eventually lead to heart damage.

  • Encephalopathy

    Any disease causing deterioration of the brain

  • Endemic

    Commonly occurring in a particular population or geographic region

  • Endocarditis

    Inflammation of the membranes lining the interior of the heart and heart valves

  • Endocrine

    Cells or tissue that produce hormones released into the bloodstream that have an affect on other cells; for example, the thyroid gland produces thyroid hormone that affects metabolism of many cells.

  • Endogenous

    Originating in or produced within an organ, tissue, cell or by the body. The term may be used to distinguish between an internal or external source of a substance, such as insulin or testosterone.

  • Endometriosis

    Condition marked by the presence, growth, and function of endometrial tissue (lining of the uterus) outside of its normal location in such sites as the uterine walls, the fallopian tubes, the ovaries, and other sites within the pelvis or, rarely, out of the pelvic region

  • Enzyme

    Protein produced in cells that speeds up the rate of biological reactions; the names of many enzymes end in -ase” (e.g.

  • Eosinophil

    Leukocyte (white blood cell) with granules that are stained by the dye, eosin. Eosinophils, normally about 1-3% of the total white blood cell count, are believed to function in allergic responses and in resisting some infections.

  • Epidemic

    Outbreak of an infectious disease that spreads rapidly among a population in a defined geographic area

  • Erectile dysfunction

    Repeated inability to achieve or sustain an erection

  • Exchange Transfusion

    Removal of some of a person’s blood and its replacement with equal amounts of donor blood

  • Exocrine

    Cells or tissue that produce substances that are released through a duct and into another organ; for example, the pancreas releases digestive juices into the intestine.

  • Exogenous

    External, originating outside of an organ, tissue, cell or the body. It may refer to a substance that is administered to the body, such as exogenous insulin or testosterone.

  • Exudate

    Fluid that has leaked into a body cavity as a result of injury or inflammation; it has a higher than normal protein content and may be cloudy due to increased numbers of white blood cells.


  • False-Negative

    Test or procedure result inappropriately indicating a normal or negative result when, in fact, an abnormal condition is actually present.

  • False-Positive

    Test or procedure result inappropriately indicating a positive or abnormal result when, in fact, no abnormal condition is actually present.

  • Febrile

    Characterized by fever; feverish

  • Feedback System

    The body uses feedback systems to control certain functions. A feedback system uses one of the products of a pathway, usually the end product, to control the activity of the pathway and to regulate the amount of that product. Feedback control may be positive or negative.

    To understand negative feedback, think of how the thermostat in your house controls the temperature. Lets say that the thermostat is set at 70 degrees F (the end product concentration). When the temperature falls below 70 degrees F, the feedback system is triggered and the furnace lights and starts to pump warm air into the house. When the air in the house reaches 70 degrees F, the thermostat shuts off the furnace (no more product made; no more hot air generated). A negative feedback system maintains a steady state or equilibrium and is the one most commonly found in the body.

    Positive feedback systems increase the rate of formation of the product. This tends to cause change in the system rather than maintain a steady state. Think of how when a person works hard and is praised for their efforts (given positive feedback), they work harder still, expecting more praise. There are very few positive feedback systems in the body. One example, however, is lactation. The suckling action of an infant produces prolactin, which leads to milk production; more suckling leads to more prolactin, which in turn leads to more lactation. This is a positive feedback system as the product (milk) produces more suckling and more hormone. When the child is no longer breast feeding, the prolactin drops off and milk production goes down.

  • Fibroid

    Incorrect but commonly used name for leiomyoma, a frequent benign smooth muscle tumor of the uterus

  • Fibrosis

    Abnormal formation of tissue that is tough, sinewy, resembling fibers

  • Fluorochrome

    a dye that gives off specific colors of light (fluoresces) when struck by light rays, often in the ultraviolet light region

  • Folliculitis

    Infected hair follicles

  • Fragile X Syndrome

    The most common inherited cause of mental retardation; takes its name from the appearance of the stained X chromosome under a microscope – there is a site near the end of this chromosome that does not stain, indicating its fragility. The gene in the fragile region is important in making a special protein needed by developing brain cells.

  • Functional Testing

    Functional testing is used to determine whether or not a specific substance is properly performing its biological role in the body and to what extent. This testing can determine how well a specific coagulation factor is performing its role in the coagulation cascade; for example, normal amounts of fibrinogen can be present, but if not working properly, abnormal coagulation results. Functional testing can also determine the correct level of activity of other substances such as hormones and enzymes.

  • Fungus

    Plural: Fungi
    One of the four major groups of microorganisms (bacteria, viruses, parasites and fungi) that occurs in nature as a yeast (small unicellular structure similar to bacteria) or a mold (large filamentous forms that may be seen with the naked eye)

  • Fusion gene

    Fusion genes are the result of chromosomes breaking and rejoining incorrectly so that two different genes are joined together. The new locations of the genes or the combination of the genes themselves may produce a new protein or effect. Often, the normal function of one of the genes involved is altered in such a way that it then promotes cell growth without responding to the normal checks and balances that cells use to stay healthy, which can lead to cancer.


  • Galactorrhea

    Breast milk production that occurs without pregnancy

  • Ganglioside

    Type of substance found on the surface of cells, particularly in the brain, that is important in cell-to-cell communication

  • Gene

    Basic unit of genetic material; in humans, a segment of DNA on a chromosome that usually codes for the production of a specific protein

  • Gene expression

    Properties exhibited by an organism due to genes present in cells

  • Gene Sequence

    Section of genetic code; particular arrangement of nucleotides along a segment of DNA on a chromosome

  • Genetic Counseling

    Process of determining the risk of a particular genetic disorder occurring within a family and providing information and advice based on that determination

  • Genetic variant

    Differences in the genes that make up our DNA are referred to as variations” or “variants” and they have different effects on the body. Most genetic variations in DNA do not affect a person’s health. Sometimes

  • Genome

    The total of a person’s genetic information

  • Genotype

    Specific combination of genes within a cell or cells

  • Germ cell

    Reproductive cell that develops into a sperm in males and an egg in females; germ cells contain one-half of the normal complement of the 46 chromosomes from each parent.

  • Gestation

    Period of development of a fetus between the time an egg is fertilized and birth

  • Gigantism

    A condition in children resulting from excess growth hormone characterized by an abnormal growth of the long bones and increased size of feet and hands

  • Globulin

    Collective term for most blood proteins other than albumin

  • Glomerulus

    Plural: glomeruli; one of a number of specialized structures in the kidney, composed of loops of specialized capillaries that filter blood, allowing small substances to pass through towards the urine but preventing loss of larger proteins and blood cells.

  • Glycogen

    The principal storage form of glucose found primarily in the liver and the muscles.

  • Goiter

    An enlarged thyroid gland

  • Granuloma

    Special form of chronic inflammation; often forms one or more nodules that can involve the skin, lymph nodes, lung, liver, spleen, or other organs. Granulomas often form in response to certain types of infection (especially to mycobacteria such as in tuberculosis and to fungi) or to foreign bodies, but sometimes have no known cause, as in sarcoidosis.

  • Gynecomastia

    Enlargement of breast tissue in the male


  • Half-life

    The amount of time it takes for the body to inactivate or metabolize half of a substance; a second half-life would decrease the remainder by half again, and so on.

  • Heinz Bodies

    Precipitated hemoglobin that can be seen inside red blood cells under the microscope

  • Hematopoietic stem cell transplantation

    Transplantation of the cells that are able to develop into all the types of blood cells; hematopoietic stem cells are usually obtained from circulating blood (peripheral), bone marrow, or umbilical cord blood. This type of transplant may use the person’s own stem cells (autologous) or stem cells from a donor (allogenic).

  • Hemodialysis

    A procedure that removes waste substances from the circulating blood; often performed on patients with kidney disease

  • Hemoglobinopathy

    A group of single gene disorders including structural hemoglobin variants (e.g., sickle cell hemoglobin) and the thalassemias

  • Hemolysis

    Process by which red blood cells disintegrate, releasing their contents

  • Hemolytic Disease of the Newborn

    A condition in which antibodies in a pregnant woman’s blood cross the placenta and destroy her baby’s red blood cells; develops when the mother and baby have differences in one or more blood group antigens

  • Hemolytic Uremic Syndrome

    A life-threatening condition that may result from the breakdown (hemolysis) of a large number of red blood cells (RBCs) and damage to the kidneys (uremia). Most often it presents as a complication of an infection of the digestive tract caused by certain bacteria that produce a toxin that enters the bloodstream and destroys RBCs. This syndrome is most commonly associated with infections caused by shiga toxin-producing Eschericha coli (STEC), but may also result from infections caused by Salmonella and Shigella, other types of infections, and sometimes from non-infectious causes.

  • Hemorrhage

    1. bleeding; escape of blood, usually from injured blood vessels
    2. excessive bleeding over a short period of time, either internally or externally; if uncontrolled, can lead to shock and death.

  • Hemorrhoid

    Swelling of vein(s) in the lower part of the rectum or anus

  • Hemosiderosis

    Abnormal deposition of an iron-containing compound (hemosiderin) in tissues, often associated with diseases in which there is extensive destruction of red blood cells (e.g., thalassemia)

  • Hemostasis

    The stopping of bleeding or the flow of blood

  • Hepatocellular carcinoma

    Cancer that originates in the cells of the liver; this type of cancer may develop in those who have certain forms of cirrhosis or who have had a hepatitis B or hepatitis C infection; may develop years after initial infection.

  • Hereditary

    Genetic; passed from parent to offspring

  • Heterophile Antibody

    A human antibody that reacts with proteins from another species; may lead to innaccurate results in immunoassay tests; sometimes used to refer to antibodies associated with infectious mononucleosis

  • Heterozygous

    Having two different copies of a particular gene, one of which may be abnormal

  • Hirsutism

    Abnormal hairiness, especially an adult male pattern of hair distribution in a female

  • Homozygous

    Having two identical copies of a particular gene, either both normal or both abnormal

  • Hormone

    A chemical substance produced and secreted by endocrine (ductless) glands that travels through the bloodstream and controls or regulates the activity of another organ or group of cells – its target organ. (For example, growth hormone released by the pituitary gland controls the growth of long bones of the body.) There are two main types of hormones – steroids (e.g., estrogen, testosterone, aldosterone, cortisol) and nonsteroidal. Secretion of hormones is regulated by feedback mechanisms and neurotransmitters.

  • Human leukocyte antigens

    Group of proteins present on the surface of white blood cells (leukocytes) and other nucleated cells (containing a nucleus). These proteins help the body’s immune system to identify its own cells and to distinguish between “self” and “nonself.” Each person has an inherited combination of HLA antigens and, while not as unique as a fingerprint, the presence or absence of each antigen creates a distinctive HLA combination for each person. HLA antigens are divided into types: Class I (A, B, C) and Class II (DR, DP, DQ).

  • Hydrocephalus

    A condition in which the chambers (ventricles) within the brain become enlarged due to an abnormal accumulation of cerebrospinal fluid

  • Hydropic

    Retaining excessive amounts of fluids

  • Hypercalcemia

    Higher than normal calcium level in the blood

  • Hyperglycemia

    Higher than normal glucose levels in the blood

  • Hyperinsulinemia

    Elevated levels of insulin in the blood

  • Hyperkalemia

    Higher than normal potassium levels in the blood

  • Hyperlipidemia

    Higher than normal cholesterol and/or triglyceride levels in the blood

  • Hyperlipoproteinemia

    Higher than normal lipoprotein levels in the blood

  • Hypernatremia

    Higher than normal sodium levels in the blood

  • Hyperparathyroidism

    A condition characterized by an overproduction of parathyroid hormone (PTH), a hormone that controls calcium and phosphate levels in blood and calcium in bone; it is made by the parathyroid glands. Primary hyperparathyroidism causes high calcium and low phosphate levels, and can cause kidney stones occasionally. Secondary hyperparathyroidism is caused by low levels of calcium or vitamin D, or high levels of phosphate; it is commonly caused by chronic kidney disease. Either form can cause osteoporosis or bone pain.

  • Hyperpituitarism

    Condition caused by increased production of pituitary hormones

  • Hyperplasia

    An increase in the number of cells in an organ, causing enlargement of that organ; this term most often refers to glandular organs, such as the prostate and the adrenal glands. Hyperplasia can produce problems related to a gland’s larger size (as in benign prostatic hyperplasia) or excess functioning of the gland (as in adrenal hyperplasia).

  • Hypocalcemia

    Lower than normal calcium level in the blood

  • Hypochromic

    Paler than normal red blood cells

  • Hypofibrinogenemia

    Low production of fibrinogen

  • Hypoglycemia

    Lower than normal glucose levels in the blood

  • Hypogonadism

    A condition associated with defective function of the gonads (ovaries in females, testes in males) resulting in little or no production of hormones

  • Hypokalemia

    Lower than normal potassium levels in the blood

  • Hyponatremia

    Lower than normal sodium levels in the blood

  • Hypoparathyroidism

    A condition characterized by underactivity of the parathyroid glands and reduced production of parathyroid hormone (PTH), a hormone that controls calcium and phosphate levels in blood and calcium in bone. Symptoms may include tingling in the fingers and toes, muscle aches and spasms, fatigue, dry skin and brittle nails, headaches, anxiety, and depression.

  • Hypopituitarism

    Condition caused by a decrease in or loss of production of pituitary hormones

  • Hypothalamus

    Area of the brain located just above the brainstem that controls the pituitary gland and regulates many bodily functions, such as body temperature, hunger, thirst, sleep, and mood through the release of hormones

  • Hypoxia

    Lack of oxygen


  • Idiopathic

     A disease or condition that does not have an identifiable cause

  • Immune System

    The body’s means of protection against microorganisms and other foreign substances; it is composed of two major parts: the humoral response (B lymphocytes and production of antibodies) and the cell-mediated response (T lymphocytes that attack foreign substances directly). 

  • Immunity

    1) Resistance to infection because of previous exposure to an infectious agent naturally or by vaccination

    2) State of activation of the immune system to recognize a foreign substance

  • Immunocompromised

    Reduced ability of one’s immune system to mount a normal response to infection

  • Immunoglobulin A (IgA)

    One of the five classes of immunoglobulins; one of the most common immunoglobulins

  • Immunoglobulin D (IgD)

    One of the five classes of immunoglobulins; it is present in small amounts in serum and is thought to function in certain allergic responses

  • Immunoglobulin E (IgE)

    One of the five classes of immunoglobulins; it is present primarily in the skin and mucous membranes and is believed to function in response to environmental antigens and to play a role in allergic reactions.

  • Immunoglobulin G (IgG)

    One of the five classes of immunoglobulins; widespread in the body

  • Immunoglobulin M (IgM)

    One of the five classes of immunoglobulins; a large molecule

  • Immunoglobulins

    Also known as: Ig; Antibody; Immune serum globulin; Immune globulin; Gamma globulin

    1) Special proteins produced by the body in response to foreign substances including bacteria and viruses; there are five structurally distinct classes of immunoglobulins produced by plasma cells in the bone marrow and other lymphoid tissue that bind to and neutralize foreign substances (antigens). The five major kinds of immunoglobulins are A, D, E, G and M.

    2) A solution made from human blood plasma that contains concentrated antibodies that protect against specific diseases, such as short-term protection against certain infections and Rh sensitization during pregnancy; it is made from human blood plasma that has been pooled, processed from donated blood, and purified.

  • Immunosuppressive

    Pertaining to a substance that decreases the body’s normal immune response

  • Impetigo

    Shallow, fluid-filled blisters surrounded by yellow crusts

  • in situ

    1. confined to the original site 

    2. in the original position

  • In utero

    Within the uterus

  • In vitro

    Outside the body; in the clinical lab, in an artificial environment such as a test tube or petri dish

  • In vivo

    Within the body; within a living environment

  • Incidence

    Rate at which new cases of a disease occur within a population

  • Incubation period

    Time between exposure to an infectious agent, such as a virus, and the onset of symptoms of disease

  • Infarction

    Tissue death caused by the blockage of blood flow by a blood clot or other material

  • Infection

    Disease caused by microorganisms

  • Inflammation

    The response of body tissues to injury such as trauma or infection. Inflammation is a complex process that can be localized or systemic. When localized, it causes pain, heat, swelling and redness of the affected area; when systemic, it may present as a general feeling of malaise with fatigue and fever.

  • Inhibitor

    1) A substance that stops, blocks, or slows down the action of an enzyme
    2) A substance that stops or impedes a process from taking place in the body

  • Insulinoma

    A tumor of the insulin-producing islet cells in the pancreas, causing low blood glucose levels

  • Intramuscular

    Within a muscle, as an injection

  • Intravenous

    Into or within a vein

  • Invasive cancer

    cancer that has spread from its place of origin in an organ or body part to surrounding tissue in the same organ or body part or to immediately adjacent tissues or organs

  • Ischemia

    Decreased supply of blood and therefore oxygen to tissue, organ (heart, brain) or body part often caused by a blockage or constriction of blood vessels

  • Islet cells

    Specialized cells in the pancreas that produce and secrete one of several hormones that affect certain body functions; some examples include alpha cells that produce glucagon and beta cells that produce insulin.


  • Joint

    Point where two or more bones meet in the body; they allow the body to be flexible and are classified by their range of movement: immovable (fibrous) do not move, such as in the skull, slightly movable (cartilaginous) as in the vertebrae in the spine, or freely movable (synovial) as in the knees and elbows, which move in many directions and are further classified as hinge, pivot or ball-and-socket joints.


  • Keratin

    A fibrous protein found in the hair, nails, and outer layer of the skin

  • Ketoacidosis

    Abnormal increase of acid in the blood due to accumulation of substances derived from metabolism of fat (ketone bodies); usually due to severe insulin deficiency in diabetes or to prolonged lack of carbohydrate intake

  • Ketones

    Byproducts of fat metabolism; may be found in urine or blood if a person does not eat enough carbohydrates or if the persons body cannot use them properly, such as with diabetes mellitus

  • Klinefelter syndrome

    A rare genetic condition in boys and men caused by an extra X chromosome. (Males normally have one X and one Y chromosome.) The presence of the extra X chromosome may or may not produce obvious signs and symptoms (usually in teens and adults), such as low testosterone, small penis and testicles, enlarged breasts, tall stature and/or behavioral, learning, speech or language disabilities. Most of these individuals are infertile.


  • Latent

    Condition or infectious agent that is present in the body but not causing symptoms and/or actively multiplying; the condition may progress from a latent to active form if the immune system of the patient is no longer able to hold the condition or infection in check.

  • Leukocytosis

    Increase in the number of white blood cells (WBC)

  • Leukopenia

    Decrease in the number of white blood cells

  • Lipemic

    Containing high levels of lipids or fats in the blood

  • Lipids

    Any of a group of fats and fat-like substances, including oils, waxes, steroids, and triglycerides. Lipids are easily stored in the body, and triglycerides serve as a fuel source. Some (such as cholesterol and phospholipids) are an important constituent of cell structures and are involved in many biological functions. Lipids can combine with other compounds to form complexes, such as lipoproteins, phospholipids, and glycolipids.

  • Lipoprotein

    Protein in the blood whose primary purpose is to transport cholesterol, tryglycerides, and other fats throughout the body

  • Lumbar puncture

    The lumbar puncture (also known as spinal tap) is usually performed while you are lying on your side in a curled up fetal position but may sometimes be performed in a sitting position. It is important that you remain still during the procedure.

    Once you are in the correct position, your back is cleaned with an antiseptic and a local anesthetic is injected under the skin. When the area has become numb, a special needle is inserted through the skin, between two vertebrae, and into your spinal canal. An “opening” or initial pressure reading of the cerebrospinal fluid (CSF) is obtained. The healthcare practitioner then collects a small amount of CSF in multiple sterile vials. A “closing” pressure is obtained, the needle is withdrawn, and a sterile dressing and pressure are applied to the puncture site. You will then be asked to lie quietly in a flat position, without lifting your head, for one or more hours to avoid a potential post-test headache.

    The lumbar puncture procedure usually takes less than half an hour. For most patients, it is a moderately uncomfortable procedure. The most common sensation is a feeling of pressure when the needle is introduced. Let your healthcare provider know if you experience a headache or any abnormal sensations, such as pain, numbness, or tingling in your legs, or pain at the puncture site.

    The lumbar puncture is performed low in the back, well below the end of the spinal cord. There are spinal nerves in the location sampled, but they have room to move away from the needle. There is the potential for the needle to contact a small vein on the way in. This can cause a “traumatic tap,” which just means that a small amount of blood may leak into one or more of the samples collected. While this is not ideal, it may happen a certain percentage of the time. The evaluation of your results will take this into account.

  • Lymphatic system

     (also Lymph, Lymph tissue, Lymph node)

    The extensive network of nodes, vessels, and ducts that collects lymph from tissues and carries it in one direction to the blood. Lymph is clear, watery fluid consisting of a number of substances including fat, protein and lymphocytes, the white blood cells that fight infections. Lymph and the lymphatic system serve to transport these substances, remove fluid and bacteria from tissues, and supply mature lymphocytes to the blood.

  • Lymphocyte

    Leukocyte (white blood cell) that normally makes up about 25% of the total white blood cell count but can vary widely. Lymphocytes occur in two forms: B cells, which produce antibodies, and T cells, which recognize foreign substances and process them for removal.

  • Lynch Syndrome

    Also known as hereditary nonpolyposis colon cancer or HNPCC.
    An inherited condition that increases the risk of many types of cancer, especially colon cancer. People who inherit mutations in the MLH1, MSH2, MSH6, PMS2, or EPCAM gene have an increased risk of developing Lynch syndrome. Besides colon cancer, examples of other cancers associated with Lynch syndrome include cancers of the stomach, liver, bile ducts, brain, skin, ovaries and lining of the uterus (endometrium).


  • Macrophage

    A large white blood cell (WBC) found in connective tissue, lymph nodes, spleen, bone marrow and other tissues; it is an important part of the body’s immune system and helps fight infections by surrounding and ingesting disease-causing microorganisms.

  • Malignant

    Harmful and potentially fatal

  • Mammogram

    Examination of the breast by X-ray

  • Mast cell

    A type of tissue cell found throughout the body but especially in connective tissue such as the skin, lining of the intestine and air passages as well as in the bone marrow. Mast cells contain granules that store chemicals. These chemicals are released as part of the body’s normal response to injury but also may be released as part of an allergic response to exposure to an allergen. The chemicals that are released can cause the allergic signs and symptoms.

  • Mastocytosis

    Abnormal accumulation of mast cells within one or more organs. Mast cells are a type of tissue cell found throughout the body that release chemicals as part of the body’s normal response to injury but sometimes as part of an allergic response. Cutaneous mastocytosis is a benign disease of the skin, usually affecting children. Systemic mastocytosis affects mostly adults, who may experience signs and symptoms related to the organs affected such as skin rashes or characteristic red, blistering lesions, peptic ulcers, chronic diarrhea, joint pain or enlargement of the liver, spleen, or lymph nodes. Systemic mastocytosis may progress slowly or may be aggressive, causing organ dysfunction and, in rare cases, causing a form of leukemia.

  • Meconium ileus

    A condition in newborn infants characterized by no stools in the first 24 to 48 hours of life

  • Megakaryocytes

    Large cells in the bone marrow that produce blood platelets

  • Meninges

    Layers of tissue that surround the brain and spinal cord

  • Mesothelioma

    Rare cancer of the membranes that cover the outside of internal organs and line body cavities, including the chest (pleural mesothelioma), abdominal cavity (peritoneal mesothelioma), and the heart (pericardial mesothelioma)

  • Metabolism

    Chemical reactions that occur in living organisms to convert one substance into another or produce energy

  • Metabolite

    Product of chemical or biological processes in the body

  • Metastasis

    Spread of cancer from its site of origin to distant sites

  • Microaerophilic

    Living or occurring in a reduced-oxygen environment

  • Microcephaly

    a birth defect in which a baby’s head is much smaller than expected and the brain is underdeveloped; this condition can occur because a baby’s brain stops developing during pregnancy or stops growing after birth. A more serious, extreme form called severe microcephaly can occur during pregnancy when a baby’s brain does not develop properly or begins to develop but then stops. Babies born with microcephaly can have several other issues, such as developmental delays, intellectual disabilities, hearing loss, problems with vision, and seizures.

  • Microcytic

    Smaller than normal red blood cells

  • Microorganism

    Life form that is not visible to the naked eye such as bacteria, fungi, parasites, and viruses

  • Mole

    a growth on the skin comprised of a cluster of skin cells that produce the skin pigment melanin (melanocytes); a mole is often raised and dark in color.

  • Monoclonal antibody

    Antibody produced by or derived from a single type (clone) of plasma cell

  • Monoclonal cells

    Group of cells derived from a single type (clone) of cell; the cells formed are identical.

  • Monoclonal gammopathy

    Abnormal condition in which clones of a single plasma cell or B lymphocyte produce greatly increased amounts of an immunoglobulin molecule; analysis of serum or urine will show a distinct monoclonal” band

  • Monocyte

    Leukocyte (white blood cell) that functions in the ingestion of bacteria and other foreign particles. Monocytes make up 5-10% of the total white blood cell count.

  • Musculoskeletal

    Pertaining to system of bones, muscles, joints, and associated tissues (e.g., ligaments and tendons) of the body involved in the maintenance of body form and movement

  • Mutation

    Change in the genetic structure (DNA); it may occur spontaneously or be induced (e.g., by radiation, drugs, or certain mutagenic chemicals).

  • Mycobacteria

    A diverse group of rod-shaped bacteria that include Mycobacterium tuberculosis (which causes tuberculosis) and Mycobacterium leprae (which causes leprosy) and more than 100 different species found in the environment; the environmental mycobacteria may be referred to as nontuberculous mycobacteria (NTM), mycobacteria other than tuberculosis (MOTT), and/or atypical mycobacteria.

  • Myelin

    The fatty covering that insulates nerve fibers


  • Narcolepsy

    A chronic condition characterized by sudden uncontrolled sleep spells during the day

  • Nasopharyngeal swab

    A nasopharyngeal swab is a respiratory sample that may be collected when you are tested for certain respiratory infections. It is collected by having you tip your head back and then a swab (like a long Q-tip with a small head) is gently inserted through one of your nostrils until resistance is met. It is left in place for several seconds, then rotated several times to collect cells, and withdrawn. This is not painful, but it may tickle, cause your eyes to tear, and provoke a coughing spell.

  • Nasopharynx

    The area at the back of the nasal passages and above and behind the soft palate

  • Neonate

    Newborn in its first month of life 

  • Nephrotic Syndrome

    Damage to the glomeruli capillaries in the kidneys’ filtering units, the nephrons; it leads to the loss of albumin and other proteins into the urine.

  • Neuroendocrine

    1. Pertaining to the interaction between the nervous system and glands that produce hormones
    2. Relating to or involving cells that produce hormones in response to the stimulation of nerves or the nervous system

  • Neurofibrillary tangles

    A collection of twisted protein filaments found within nerve cells in the brains of people with Alzheimer’s disease

  • Neurologic

    Pertaining to nerves and the nervous system, including the brain and spinal cord

  • Neutropenia

    Decreased number of neutrophils, a type of white blood cell

  • Neutrophil

    Normally the most abundant type of white blood cell in healthy adults

  • Next Generation Sequencing

    A type of laboratory test method that rapidly sequences large amounts of DNA; sequencing determines the order of DNA building blocks (nucleotides) in a person’s genetic code. Changes in the building blocks (mutations) in the regions of DNA that are responsible for making proteins can lead to genetic disorders. Next-gen sequencing can look for mutations in any of the protein-producing regions of DNA.

  • Non-palpable

    Not perceivable by touch

  • Normal flora

    Microorganisms that live harmlessly on or in the body and do not cause disease unless the normal protective barriers (skin, mucosa) are compromised

  • NSAIDs

    Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are a group of painkillers that includes drugs such as ibuprofen and aspirin; they reduce fever as well as decrease pain and inflammation; can cause side effects such as stomach ulcers.

  • Nucleus

    The structure in cells that contains the chromosomes, genes, DNA.

  • Nutrient Medium

    Material that provides the proper nutritional environment to promote the growth of microorganisms


  • Oligoclonal bands

    Discrete bands observed on an electrophoretic gel as a result of a patients sample being analyzed by protein electrophoresis

  • Oncogene

    Genetic material that is able to produce a malignant change in a cell; several have been identifited in human tissue as potential causes of cancer. Certain oncogenes may play a role in normal growth and development; if they are damaged or mutated, cancer may result.

  • Opportunistic Infection

    Infection that affects people with suppressed immune systems

  • Oral

    Pertaining to the mouth

  • Organ

    A specific stucture in the body that performs one or more functions, such as the heart, lungs or liver

  • Osteoblast

    Specialized bone cell that produces and deposits the material (mostly collagen) that forms new bone tissue

  • Osteoclast

    Specialized bone cell that secretes enzymes that break down bone tissue; the cell then resorbs the dissolved bone material.

  • Osteomalacia

    A bone disease that occurs in adults when a prolonged period of vitamin D deficiency results in soft, weak bones; when this condition occurs in childhood, it is called rickets.

  • Over-expressed

    Increased level (amounts) of a gene that results in the production of more than the normal amount of protein

  • Ovum


  • Oxidative Stress

    Damage to cells in the body caused by free radicals; free radicals, groups of atoms containing an oxygen atom and a free electron, can damage and sometimes destroy cells.


  • Paget Disease

    1) The most common use of the term refers to a bone disorder in which bone is formed and broken down excessively, resulting in weakened bones. This condition can cause bone pain, deformed bones, arthritis, and numerous fractures.

    2) Other, less common uses of the term refer to rare forms of cancer involving the nipple of the breast or the skin of other areas such as the perianal region, penis, or vulva (also termed extramammary).

  • Pallor

    Pale skin color

  • Pandemic

    An epidemic that occurs over a wide geographic area (across continents)

  • Paraganglioma

    tumor that releases excess hormones called catecholamines (e.g., dopamine, epinephrine (adrenaline), norepinephrine and their metabolites, such as metanephrines) and usually occurs somewhere in the abdomen but outside the adrenal glands

  • Parasite

    One of the four major groups of microorganisms (bacteria, viruses, fungi, and parasites) that may live freely in nature, live on another organism without harming it, or live at the expense of the host organism

  • Parenteral

    Administration of a substance (e.g., a drug) by injection (under or through the skin) or intravenously but not through the digestive system (not enterally)

  • Paresthesia

    numbness, tingling, or prickling; an alteration in sensation

  • Parietal

    1) Of or pertaining to the cells that line a cavity, such as the chest or abdomen;

    2) A specialized cell in the stomach that makes acid to help in food digestion, as well as intrinsic factor, which is needed to absorb vitamin B12

  • Paroxysmal choreoathetosis

    A condition characterized by involuntary, intermittent, and irregular movements of facial muscles and limbs

  • Pathogen

    Organism that causes disease

  • Pathogenic


  • Pathologist

    A physician who diagnoses and characterizes disease by examining a patient’s tissues, blood, and other body fluids. Pathologists work in two broad areas:

    Anatomic pathology is the examination of the physical appearance and microscopic structure of tissues. Anatomic pathologists look at biopsies and organs removed at surgery (surgical pathology) as well as cells that are collected from brushings or body fluids (cytology). They also perform autopsies to investigate the cause of death (autopsy pathology).

    Clinical pathology deals with the measurement of chemical constituents of blood and other body fluids (clinical chemistry), analysis of blood cells (hematology), identification of microorganisms (microbiology), and the collection, preparation and use of blood for transfusion (transfusion medicine). Clinical pathologists direct the laboratories that perform these tests and provide consultation to other doctors on the significance of test results.

  • Pericardium

    Sac-like membrane that surrounds the heart and the base of the blood vessels that lead into it

  • Peripheral nervous system

    All parts of the nervous system except the brain and spinal cord

  • Peritoneum

    Membranes that cover the abdominal cavity and the outside of abdominal organs

  • pH

    Measurement of the acidity or alkalinity of a substance. A pH of 7.0 is neutral. A substance with a pH less than 7.0 is an acid, with increasing acidity as the pH decreases toward zero. Likewise, a substance with a pH greater than 7.0 is a base (alkali), with increasing alkalinity as the pH moves toward 14.0.

  • Phenotype

    The observable physical or biochemical characteristics of a person, as determined by both their genetic makeup and environmental influences

  • Pheochromocytoma

    tumor located in one or both of the adrenal glands that releases excess hormones called catecholamines (e.g., dopamine, epinephrine (adrenaline), norepinephrine and their metabolites, such as metanephrines)

  • Phospholipid

    A substance in the body that contains both lipid (fat) and phosphorous; phospholipids are found in all cells throughout the body because they are a major component of the cell membrane, the outermost layer of a cell.

  • Pituitary gland

    Pea-sized gland located in the center of the head behind the sinus cavity at the base of the brain; the pituitary consists of two parts that produce different hormones: 1) in the anterior portion, growth hormone (GH), adrenocorticotropin (ACTH), thyroid-stimulating hormone (TSH), lutenizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) are produced; 2) in the posterior portion, oxytocin and antidiuretic hormone (ADH) (produced in the hypothalamus) are stored for release.

  • Placenta

    The organ that connects a pregnant woman with her developing baby in the uterus; blood from the mother and baby do not mix directly, but a thin membrane within the placenta allows nutrients from the mother to pass to the baby and waste products to pass from the baby to the mother for elimination.

  • Plaque

    1. Deposit on the inner arterial walls in atherosclerosis
    2. Flat, raised patch on the skin or mucous membrane
    3. Deposit of saliva and bacteria on teeth that encourages the development of caries

  • Plasma

    Straw-colored, fluid part of blood and lymph

  • Plasma cell

    Mature lymphocyte (B cell) that produces and secretes antibodies

  • Pleura

    One of the two membranes that surrounds each lung and lines the chest cavity

  • Pneumonitis

    An inflammation of the lungs; usually caused by a hypersensitive allergic reaction to repeated exposure to organic particles such as molds, grain dust, and chemicals

  • Polyclonal antibody

    Antibody produced by or derived from many types (clones) of plasma cells

  • Polycythemia

    Increase in the number of erythrocytes (red cells, RBCs) in the blood

  • Polymer

    A large molecule consisting of multiple identical or similar chemical units that are linked together

  • Polymorphic

    Gene having many different possible forms (alleles)

    See also: Polymorphism

  • Polymorphism

    Inherited person-to-person variation in the genetic code sequence within a specified DNA segment or gene

    See also: Polymorphic

  • Polymyalgia Rheumatica

    A disease that causes pain and weakness in the neck, shoulder muscles and pelvis, and morning stiffness. It commonly affects people over 50 years of age, especially women.

  • Polyp

    A growth, such as on the lining of the mouth or intestines, that is usually benign; examples include uterine polyps and colorectal polyps”

  • Posterior

    At or toward the back

  • Precursor

    1. one that comes before or gives rise to another
    2. in chemistry, one substance that comes before or gives rise to another often more stable substance

  • Presumptive

    Based on reasonable evidence or assumption; based on early, preliminary or partial results

  • Prevalence

    The number of people with a particular disease at any given time in a population

  • Preventive Medicine

    That branch of medicine concerned primarily with the prevention of disease

  • Prion Protein

    An infectious agent (not bacteria or virus) that is an irregular form of a normal protein; prion proteins cause a variety of infections, including Mad Cow Disease and Creutzfeld-Jacob disease. Prion proteins are thought to induce normal brain proteins to assume an irregular shape, rendering them dysfunctional.

  • Prognosis

    1) prediction about the course or outcome of a disease or illness
    2) the likelihood of recovery from a disease or illness

  • Prophylaxis

    (adj. Prophylactic)
    1. Measure taken to prevent or protect against disease
    2. Antibiotic prescribed to prevent infection

  • Prostatitis

    inflammation of the prostate

  • Protein

    Proteins are large molecules that form the structural part of most organs and make up enzymes and hormones that regulate body functions.

  • Pruritus

    An irritating skin condition that causes a desire to scratch

  • Purpura fulminans

    Involves severe clotting throughout much of the body, ultimately causing death to the tissues. If not treated immediately, it is a life-threatening condition.

  • Pus

    Collection of fluid, white blood cells, microorganisms, and cellular material that indicates the presence of an infected wound or abscess


  • Qualitative Test Results

    Test results expressed in terms of the presence (positive) or absence (negative) of a property or condition

  • Quantitative Test Results

    Test results expressed as numbers

  • Quantity Testing

    Quantity testing measures how much of a particular substance or analyte is present. This type of testing can measure amounts of coagulation factors, hormones, enzymes, and many other substances. It does not, however, evaluate how well the substance is working or performing its role in the body.


  • Random Blood Sample

    A sample of blood collected at any time of the day

  • Random Urine Sample

    A sample of urine collected at any time of the day; this type of sample may be used to detect the presence of various substances in the urine at one particular point in the day. Often, no special handling is required with these samples. Other types of urine samples are requested when special types of evaluations are required (see 24-hour urine sample and timed urine sample).”

  • Raynaud phenomenon

    Intermittent episodes of pallor, cyanosis (bluing), and redness in the fingers or toes due to constricted blood vessels; it is seen with a variety of conditions and is precipitated by exposure to cold and emotional stress. It may cause numbness, tingling, and burning.

  • Reagent

    Substance used in performing a laboratory test

  • Recessive Gene

    One of a pair of genes whose action is expressed only when two copies are present. For example, the gene for cystic fibrosis is recessive, and the disease will not occur if one normal gene is present.

  • Resorption

    The process by which a substance, such as bone, is broken down into basic components and removed from that area of the body

  • Retina

    sensing part of the eye that collects images from the lens and translates them to chemical signals that can be interpreted by the brain

  • Reye syndrome

    A rare condition that causes degeneration of the brain and is characterized by vomiting, fever, accumulation of fat in the liver, swelling of kidneys and brain, disorientation and coma; often occurs in children and following another illness, such as the flu or chickenpox.

  • Rheumatic fever

    Condition resulting from an inadequately treated or untreated infection with Group A streptococcus bacteria. It is a delayed immune response in which the body produces antibodies directed against itself (autoimmune). This can cause serious damage to heart valves and lead to symptoms such as swelling and pain in several joints, heart inflammation (carditis), skin nodules, rapid, jerky movements (Sydenham’s chorea), and skin rash.

  • Rickets

    A condition that occurs in childhood in which a severe lack of vitamin D causes weak, soft bones, delayed growth and skeletal development; when this condition occurs in adulthood, it is called osteomalacia.

  • RNA

    RNA (ribonucleic acid) is a nucleic acid that can carry genetic information (especially in some viruses), perform various activities in the cell, and help form proteins that are encoded in DNA. Several types of RNA exist. Some lab tests measure messenger RNA (mRNA), which is a copy of the DNA code that is translated into amino acids to form a protein.


  • Senile plaque

    Areas of dead nerve cells and protein deposits in the brain

  • Sensitivity

    In the clinical laboratory:

    1. a test’s ability to correctly identify individuals who have a given disease or disorder;

    2. ability of a test to detect small amounts of a substance or to measure a reaction

  • Septicemia

    Serious infection in which disease-causing organisms are present in the blood, usually resulting from spread of an infection from a specific site

  • Sequela

    Abnormality resulting as a consequence of a disease, injury or treatment

  • Serotype

    A group of related microorganisms, such as bacteria or viruses, that possess different antigens that are distinguished as unique by the immune system

  • Serum

    The liquid portion of blood remaining after a clot forms

  • Serum Sickness

    An allergic reaction to proteins in a foreign serum, usually in response to an injection; it is characterized by symptoms such as fever, skin rash, pain and swelling in one or more joints, and kidney damage

  • Shock

    A condition in which blood flow is inadequate to keep critical organs performing properly; it is often recognized by markedly low blood pressure with evidence of poor function of the brain, kidneys, heart, and/or liver. It is a medical emergency that can lead to serious damage and/or death.

  • Shwachman-Diamond Syndrome

    A rare congenital disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and skeletal abnormalities; it is the second most common cause of inherited pancreatic insufficiency after cystic fibrosis.

  • Sideroblastic Anemia

    An iron disorder and form of anemia resulting from the inability to incorporate iron into hemoglobin in red blood cells (RBCs); it is characterized by the buildup of iron within developing RBCs resulting in abnormal RBCs called sideroblasts. Since the RBCs cannot develop normally, this condition causes anemia.

  • Sigmoidoscopy

    Examination of the rectum and lower colon with a rigid or flexible lighted instrument

  • Sign

    Evidence of a disease or condition perceived by a physician or person other than the patient

  • Somatic Cells

    All body cells, except the reproductive cells

  • Specificity

    In the clinical laboratory:
    1. a test’s ability to correctly exclude individuals who do not have the given disease or disorder;
    2. a test’s ability to correctly detect or measure only the substance of interest and exclude other substances

  • Spina bifida

    A birth defect in which the bones of the spine do not close around the spinal cord (the continuation of brain tissue that normally is surrounded by the spinal bones); this opening may be covered by skin (also called spina bifida occulta, which means hidden), in which case there may be no or mild symptoms. In other cases, the skin does not cover the defect, allowing the covering of the brain and spinal cord, the meninges, to protrude out through the skin (meningocele) or, in some cases, to rupture, exposing the spinal cord itself (meningomyelocyle). These latter two examples may cause severe damage to the nerves of the legs and lower abdomen, causing paralysis and bowel and bladder malfunction.

  • Spirochete

    Any of a group of spiral-shaped bacteria

  • Spleen

    organ located in the abdomen that functions mainly to store blood cells, remove old blood cells from circulation, produce lymphocytes to fight infection, and filter foreign substances from the blood

  • Spondylitis

    An inflammation of the vertebrae

  • Sporadic cancer”

    Sporadic cancer is the term used to describe cancers that develop in an individual as a result of chance as opposed to a strong inherited risk factor for developing cancer. Many factors influence the chance that a person will develop cancer in their lifetime, including overall health, environment, and genetics. In a sporadic cancer, it is likely that many factors have combined to produce the disease.

  • Spore

    1. Small, usually single-celled reproductive unit of some microorganisms such as fungi.

    2. Form assumed by some bacteria that is resistant to heat, drying, and chemicals; an example of a disease caused by spore-forming bacteria is anthrax.

  • Sputum

    Viscous material that is derived from the lower air passages such as the lungs and bronchi that may contain substances such as mucus, blood, pus and/or bacteria; it is not the saliva that is produced by the glands in the mouth.

  • Stage

    In medicine, a defined period or phase in the development, progress or extent of a disease or condition; the process of determining the period or phase of a disease or condition. In cancer, the stage is the degree to which the cancer has grown or spread. Generally, lower numbers and/or letters mean less extensive stages.

  • Statins

    A group of drugs that reduce the production of cholesterol and promote the clearance of low-density lipoprotein (LDL) from the blood by the liver.

  • Stem cells

    Cells that are able to develop into many (or all) types of cells

  • Stenosis

    A narrowing or constriction of a passageway in the body, such as in a blood vessel or spinal canal

  • Steroids

    A group of chemicals derived from cholesterol that typically functions as hormones; common types of steroids include sex steroids (estrogen, progesterone, testosterone), glucocorticosteroids (cortisol, prednisone, dexmethasone), and mineralacorticosteroids (aldosterone).

  • Subcutaneous

    Under the skin

  • Symptom

    Evidence of a disease or condition experienced or perceived by a patient

  • Syncope

    Fainting; loss of consciousness

  • Syndrome

    A group of signs and symptoms that are associated with a physical or physiological anomaly; they represent a frame of reference, not a cause.

  • Systemic

    Affecting the body as a whole, rather than individual parts


  • Temporal Arteritis

    Chronic inflammation and damage of large arteries in the face and head; symptoms include headache, scalp tenderness, loss of vision, and facial pain.

  • Thrombocytopenia

    A decrease in the number of blood platelets

  • Thrombophilia

    An inherited or acquired tendency to form blood clots within a vein or artery

  • Thrombosis

    The formation of a blood clot within an artery or a vein.

  • Thrombotic Episode

    The clinical signs and symptoms associated with a blood clot in a vein or artery. This can be a life-threatening event.

  • Thymus

    Organ located behind the upper breastbone at the base of the neck that is part of the lymphatic and immune systems; disease-fighting white blood cells called T-cells develop and mature in the thymus before entering circulation. In humans, the thymus is normally active in childhood but becomes less active after puberty, eventually losing most immune activity by adulthood.

  • Thyroiditis

    an inflamed thyroid

  • Timed Urine Sample

    A sample of urine collected over a specified period of time; for a short collection (2 hours), you may be asked to do this at the laboratory. For longer collections (such as 12 hours or 24 hours), you will do this at home. At the beginning of the time period, empty your bladder and discard that urine. Note the time. Collect all urine voided for the specified period of time in the container provided. At the end of the time period, empty your bladder and ADD this urine to the container. Note the time. Bring all of the urine collected to the lab or doctor’s office. If you miss collecting one or more voids, consult your doctor or the laboratory for further instructions. (See 24-hour urine sample)”

  • Tissue

    A collection of cells having a common purpose in the body, such as muscle tissue or kidney tissue

  • Titer

    In the clinical laboratory, titer is a unit of measurement. It is most often thought of as the lowest dilution of a substance in which a reaction takes place. It is usually expressed as a ratio (i.e., 1:20). For example, serum containing an antibody can be diluted with saline in a serial manner producing dilutions 1:5, 1:10, 1:20, 1:40, etc. If the lowest dilution that a reaction can still be detected between the antibody and the antigen it is directed against is 1:20, then that is the result of the antibody titer.

  • Topical

    Applied to the surface of the skin

  • Toxemia of pregnancy (Preeclampsia)

    A condition during pregnancy characterized by high blood pressure, protein in the urine, and fluid retention. If untreated, it can lead to eclampsia and convulsions that can be life-threatening to the mother and baby.

  • Toxic megacolon

    A rare but serious, potentially life-threatening condition in which all or part of the colon progressively swells and becomes gangrenous, with tissue death resulting from lack of blood supply

  • Toxicity

    Extent or degree to which something is poisonous

  • Toxin

    Generally, anything that injures, is destructive, or can cause death; specifically, a poisonous substance made within living cells or organisms (plants or animals); may also include some medicines if taken in large amounts and certain metals

  • Tracer

    In radiology, radioactive isotope (e.g., iodine-131) introduced into the body to allow biological structures to be seen as part of diagnostic X-ray techniques.

  • Translocation

    (v. translocate) In genetics, movement of one section of a chromosome to a different position on another chromosome resulting in abnormal chromosome structure

  • Transplantation

    Process of removing cells, tissue, or organ(s) from one body and inserting them into another body, especially using surgery

  • Transudate

    Fluid that has leaked into a body cavity, due to an imbalance between the pressure within blood vessels (which drives fluid out) and the amount of protein in blood (which keeps fluid in); it is a clear fluid with low protein concentration and a limited number of white blood cells.

  • Tubule

    A long, thin hollow tube; in the kidney, a structure that connects to the glomerulus and helps the kidney retain needed small substances (such as water, electrolytes, glucose, calcium) while allowing elimination of waste products. Its contents eventually drain into the collecting system of the kidney as urine.

  • Tumor

    Growth of tissue characterized by uncontrolled cell proliferation; benign or malignant, localized or invasive

  • Turner Syndrome

    A disorder involving the X chromosomes in females. Normally, there are two functioning X chromosomes in every cell in the female body. In Turner syndrome, one of the X chromosomes is missing or is abnormal, or there are two normal X chromosomes present but in only some of the cells. Women with Turner syndrome usually have underdeveloped female sexual characteristics.

  • Tyrosine kinase

    An enzyme that works by adding phosphate groups to various molecules, changing their function

  • Tyrosine kinase inhibitor

    Drug used to treat certain types of cancer; it inhibits the action of tyrosine kinase, an enzyme involved in cell growth, thus impeding the growth of cancer cells.


  • U.S. Preventive Services Task Force

    The U.S. Preventive Services Task Force (USPSTF) is an independent, volunteer panel of health professionals and experts. It regularly reviews the latest scientific evidence, such as research studies, to develop and update recommendations on various preventive services. The panel issues the findings as draft documents open for public comment before officially adopting them. The USPSTF is convened by the Agency for Healthcare Research and Quality (AHRQ) as authorized by the U.S. Congress.

  • Ulcer

    A defect in the skin or lining of the mouth or intestines resulting from an infectious, malignant

  • Ulcerative colitis

    A chronic disease of unknown cause that is characterized by inflammation, ulcers, and fluid collection in the lining of the colon; this condition may cause diarrhea with blood and/or mucus and stomach cramping and pain.

  • Ultrasound

    An imaging test that uses an instrument called a transducer or a probe to produce sound waves. When moved over or within a cavity of the body the transducer or probe produces pictures of the body’s soft tissues and organs that typically don’t show up well on x-rays. It can also be used to view a developing fetus in pregnant women.

  • Unconjugated bilirubin

    A fat-soluble form of bilirubin that is formed during the initial chemical breakdown of hemoglobin and, while being transported in the blood, is mostly bound to albumin.

  • Undifferentiated

    Cells that are immature, embryonic or primitve, and have no specific form or specialized function are said to be undifferentiated

  • Uremia

    A serious condition in which toxic waste products, normally excreted in the urine, build up in the blood; this is usually as a result of severe kidney disease or kidney failure.

  • Urethra

    Tube through which urine passes from the bladder to outside of the body; in men, it is also the tube that runs through the penis and through which semen is discharged

  • Urinary casts

    Protein shapes formed in the kidney tubules and released into the urine; they are roughly cylindrical with rounded ends and may have other components embedded in them such as red blood cells. Casts can be a sign of kidney disease.

  • Uveitis

    Painful swelling and irritation of the uvea, the middle layer of the eye (the layer just beneath the white of the eye), which causes redness without itching; it is a serious condition that can lead to loss of vision.


  • Vaccine

    A preparation designed to induce immunity to a specific disease

  • Venereal

    Pertaining to or caused by sexual intercourse or genital contact

  • Vesicle

    A small raised area of the outer layer of the skin filled with a watery liquid

  • Viral load

    Number of copies of viral genetic material

  • Virilization

    Development of masculine physical characteristics in a woman

  • Virus

    A microorganism consisting of a nucleic acid (either DNA or RNA) core and a protein coat. A virus requires a host cell to reproduce. It reproduces by infecting a host cell and taking over the nucleic acid of that host cell, making more virus nucleic acid and protein.

  • Viscosity

    Resistance of a fluid (e.g., plasma, serum, cerebrospinal fluid) to flow; thickness or stickiness of a fluid

  • Vitamin

    Any of a group of substances that, in very small amounts, are essential for normal growth, development, and metabolism. They cannot be synthesized in the body (with a few exceptions) and must be supplied by the diet.


  • Whole blood

    Blood that is not separated into fluid and cellular components after removal from the body

  • Wild-type

    The usual form of a gene in the general population, as opposed to mutant forms


  • X-linked recessive trait

    A genetic trait that is apparent when all copies of the X-chromosome possess the gene; in men, this occurs when they inherit the trait from their mother, while women must inherit the trait from both parents. For this reason, X-linked recessive traits are almost always apparent only in men, while women are more commonly carriers of the trait.

  • X-linked trait

    A genetic trait found on the X chromosome; women have two copies of this chromosome, while men have only one.