Also Known As
Diabetes mellitus
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This article waslast modified on November 2, 2018.

Note: This article addresses diabetes mellitus, not diabetes insipidus. Although the two share the same reference term "diabetes" (which means increased urine production), diabetes insipidus is much rarer and has a different underlying cause.

What is diabetes?

Diabetes is a group of conditions linked by an inability to produce enough insulin and/or to respond to insulin. This causes high blood glucose levels (hyperglycemia) and can lead to a number of acute and chronic health problems, some of them life-threatening.

Diabetes is the seventh leading cause of death in the United States. According to the Centers for Disease Control and Prevention, about 29 million people in the U.S. currently have diabetes, but as many as 8 million are not yet aware that diabetes is affecting their health.

People with diabetes are unable to process glucose, the body's primary energy source, effectively. Normally, after a meal, carbohydrates are broken down into glucose and other simple sugars. This causes blood glucose levels to rise and stimulates the pancreas to release insulin into the bloodstream. Insulin is a hormone produced by the beta cells in the pancreas. It regulates the transport of glucose into most of the body's cells and works with glucagon, another pancreatic hormone, to maintain blood glucose levels within a narrow range.

If someone is unable to produce enough insulin, or if the body's cells are resistant to its effects (insulin resistance), then less glucose is transported from the blood into cells. Blood glucose levels remain high but the body's cells "starve." This can cause both short-term and long-term health problems, depending on the severity of the insulin deficiency and/or resistance. Diabetics typically have to control their blood glucose levels on a daily basis and over time to avoid health problems and complications. Treatment, which may involve specialized diets, exercise and/or medications, including insulin, aims to ensure that blood glucose does not get too high or too low.

  • A very high blood glucose level (acute hyperglycemia) can be a medical emergency. The body tries to rid the blood of excess glucose by flushing it out of the system with increased urination. This process can cause dehydration and upset the body's electrolyte balance as sodium and potassium are lost in the urine. With severe insulin deficiency, glucose is not available to the cells and the body may attempt to provide an alternate energy source by metabolizing fatty acids. This less efficient process leads to a buildup of ketones and upsets the body's acid-base balance, producing a state known as ketoacidosis. Left unchecked, acute hyperglycemia can lead to severe dehydration, loss of consciousness, and even death.
  • A very low blood glucose level (hypoglycemia), often as a result of too much insulin, can also be life-threatening. It can lead to hunger, sweating, irregular and rapid heart beat, confusion, blurred vision, dizziness, fainting, and seizures. Severely low blood glucose can lead fairly quickly to insulin shock and death.
  • Glucose levels that rise over time and become chronically elevated may not be initially noticed. The body tries to control the amount of glucose in the blood by increasing insulin production and by eliminating glucose in the urine. Signs and symptoms usually begin to arise when the body is no longer able to compensate for the higher levels of blood glucose.

    Chronic high blood glucose can cause long-term damage to blood vessels, nerves, and organs throughout the body and can lead to other conditions such as kidney disease, loss of vision, strokes, cardiovascular disease, and circulatory problems in the legs. Damage from hyperglycemia is cumulative and may begin before a person is aware that he or she has diabetes. The sooner that the condition is detected and treated, the better the chances are of minimizing long-term complications.
     

The following table summarizes some types of diabetes. Read the sections below to learn more about the various types.

Type of Diabetes Description
Type 1 Exact cause unknown; thought to be primarily an autoimmune disease that involves the destruction of the insulin-producing beta cells in the pancreas; can occur at any age but usually diagnosed in children and young adults.
Type 2 Most common type; associated with insulin resistance and with insulin production that is insufficient to meet the body's needs and to compensate for resistance. It develops most frequently in overweight middle-aged and elderly people. With increased obesity in children and adolescents, the condition is becoming more common at younger ages.
Gestational Develops during a woman's pregnancy and affects both mother and developing baby; typically develops late in the pregnancy.
Prediabetes Higher blood glucose than normal, but not considered diabetes; people with prediabetes are at an increased risk of developing diabetes.
Other A group of less common types of diabetes. Any condition that damages the pancreas and/or affects insulin production or usage can cause diabetes.

 

Accordion Title
About Diabetes
  • Signs and Symptoms

    The signs and symptoms of diabetes are related to high glucose levels (hyperglycemia), low glucose levels (hypoglycemia), and complications associated with diabetes. Type 1 diabetics are often diagnosed with acute severe symptoms that require hospitalization. With prediabetes, early type 2 diabetes, and gestational diabetes, there usually are no signs or symptoms.

    Signs and symptoms of type 1 and type 2 diabetes with hyperglycemia may include:

    • Increased thirst
    • Increased urination
    • Increased appetite (with type 1, weight loss is also seen)
    • Fatigue
    • Nausea, vomiting, abdominal pain (especially in children) 
    • Blurred vision
    • Slow-healing wounds or infections
    • Numbness, tingling, and pain in the feet (neuropathy)
    • Erectile dysfunction in men
    • Absence of menstruation in women
    • Rapid breathing (acute)
    • Decreased consciousness, coma (acute)
       

    Symptoms of impending hypoglycemia:
    Temporary hypoglycemia in the diabetic may be caused by the accidental injection of too much insulin, not eating enough or waiting too long to eat, exercising strenuously, or by the swings in glucose levels seen with "brittle" diabetes. Hypoglycemia needs to be addressed as soon as it is noticed as it can rapidly progress to unconsciousness. Signs and symptoms include:

    • Sudden severe hunger
    • Headache
    • Anxiety, confusion
    • Sweating
    • Trembling, weakness
    • Double vision
    • Convulsions
    • Coma
  • Complications

    Complications of diabetes can be related to unhealthy lipid levels, damage to blood vessels (vascular and microvascular), organ damage such as to the kidneys (diabetic nephropathy), and nerve damage (diabetic neuropathy).

    It is important for diabetics to work closely with their health practitioners and a diabetes educator, to have regular check-ups (several times a year) that include monitoring tests such as urinary albumin (microalbumin) and A1c, and to get immediate attention for the complications listed above. Others may include:

    • Wound infections, especially on the feet; they can be slow to heal and, if not addressed promptly, may eventually lead to an amputation. Aggressive and specialized measures are often necessary, and the affected person may need to consult with a diabetic wound specialist, a health practitioner trained in working with the altered healing of diabetics.
    • Diabetic retinopathy, which can lead to eye damage, a detached retina, and blindness; laser surgery can often be used to reattach the retina.
    • Urinary tract infections, which can be frequent and resistant to antibiotic treatment; delayed or inadequate treatment can lead to or exacerbate kidney damage.
  • Tests

    The goals of diabetes testing are to screen for high blood glucose levels (hyperglycemia), to detect and diagnose diabetes and prediabetes, to monitor and control glucose levels over time, and to detect and monitor complications.

    Tests may be used:

    • When someone has signs and symptoms suggesting diabetes
    • When a person has risk factors or a condition that is associated with diabetes
    • When a person presents to the emergency room with an acute condition
    • On a regular basis, to monitor diabetes and glucose control
       

    Screening for diabetes that occurs during pregnancy (gestational diabetes) is different than testing the general population. See the section on Gestational Diabetes for more on this.

    According to the American Diabetes Association, a few different tests may be used for screening and diagnosis of diabetes or prediabetes and each test has advantages, disadvantages, and limitations. If the initial screening result from one of the tests listed below is abnormal, the test is repeated on another day. The repeat result must be abnormal to confirm a diagnosis of diabetes. Tests include:

    • Fasting glucose (fasting blood glucose, FBG) – this test measures the level of glucose in the blood after an 8-12 hour fast.
       
    Fasting Glucose Level Indication
    From 70 to 99 mg/dL (3.9 to 5.5 mmol/L) Normal fasting glucose
    From 100 to 125 mg/dL (5.6 to 6.9 mmol/L) Prediabetes (impaired fasting glucose)
    126 mg/dL (7.0 mmol/L) and above on more than one testing occasion Diabetes

     

    • A1c (also called hemoglobin A1c or glycohemoglobin) – this test evaluates the average amount of glucose in the blood over the last 2 to 3 months. For the A1c test, people don't have to fast for 8 hours or endure multiple blood samples being taken over several hours, but the test is not recommended for everyone. It should not be used for diabetes diagnosis in pregnant women, people who have had recent severe bleeding or blood transfusions, those with chronic kidney or liver disease, or people with blood disorders such as iron-deficiency anemia, vitamin B12 anemia, and hemoglobin variants. Also, only A1c tests that have been referenced to an accepted laboratory method (standardized) should be used for diagnostic or screening purposes. Currently, point-of-care tests, such as those that may be used at a doctor’s office or a patient’s bedside, are too variable for use in diagnosis but can be used to monitor treatment (lifestyle and drug therapies).

     

    A1c Level Indication
    Less than 5.7% (39 mmol/mol) Normal
    5.7% to 6.4% (39-46 mmol/mol) Prediabetes
    6.5% (47 mmol/mol) or higher Diabetes
    • 2-hour glucose tolerance test (OGTT) – this test involves drawing a fasting blood test, followed by having a person drink a 75-gram glucose drink and then drawing another sample two hours after consuming the glucose.
       
    Glucose Level 2 Hours After 75-gram Drink Indication
    Less than 140 mg/dL (7.8 mmol/L) Normal glucose tolerance
    From 140 to 199 mg/dL (7.8 to 11.1 mmol/L) Prediabetes (impaired glucose tolerance)
    Equal to or greater than 200 mg/dL (11.1 mmol/L) on more than one testing occasion Diabetes
    • Sometimes a blood sample may be drawn and glucose measured when a person has not been fasting, for example, as part of a comprehensive metabolic panel (CMP). A result of 200 mg/dL (11.1 mmol/L) or higher indicates diabetes. An abnormal result may be followed up with additional testing.
       

    For screening only:

    • Sometimes urine samples are tested for glucose, protein, and ketones, often as part of a urinalysis, during a routine physical examination. If glucose and/or protein or ketones are present in the urine sample, the person has a problem that needs to be addressed. Additional testing is usually done to identify the cause of the abnormal urine result.
       

    Tests for monitoring:

    • Glucose – type 1 diabetics must monitor their own blood glucose levels, often several times a day, to determine how far above or below normal their glucose is and, based on their healthcare provider's instructions, what modifications they should make to their medications. This is usually done by placing a drop of blood (obtained by pricking the skin with a small lancet device), onto a glucose strip and then inserting the strip into a glucose meter, a small machine that provides a digital readout of the blood glucose level. Some type 2 diabetics and pregnant women diagnosed with gestational diabetes may also need to monitor their blood glucose in this way.
    • A1c and estimated average glucose (eAG) – this is a test and a calculation that are ordered several times a year to monitor diabetics and sometimes people with prediabetes. A1c is a measure of the average amount of glucose present in the blood over the last 2 to 3 months and helps a health practitioner to determine how well a treatment plan is working to control someone's blood glucose levels over time.
       

    Several other laboratory tests may be used to evaluate glucose control, organ function, and to detect emerging complications. These may include:

Accordion Title
Diabetes Types
  • Type 1 diabetes

    Type 1 diabetes, which used to be called insulin dependent or juvenile diabetes, makes up about 5% of the diabetes cases in the United States. Most cases of type 1 diabetes are diagnosed in those under the age of 30. Type 1 diabetics make very little or no insulin. Any insulin-producing beta cells they do have at the time of diagnosis are usually completely destroyed within 5 to 10 years, leaving them entirely reliant on insulin injections to live.

    The exact cause of type 1 diabetes is unknown, but a family history of diabetes, viruses that injure the pancreas, and autoimmune processes, in which the body's own immune system destroys the beta cells, are all thought to play a role. Type 1 diabetics may have more severe medical complications sooner than other diabetics. About 40% of those with type 1 diabetes will develop serious kidney problems leading to kidney failure by the age of 50.

    Signs and Symptoms

    Signs and symptoms in type 1 diabetes often develop abruptly and the diagnosis is often made in an emergency room setting. The affected person may be seriously ill, even comatose, with very high glucose levels and high levels of ketones (ketoacidosis) and may require hospitalization. See the section on Signs and Symptoms for more detailed information.

    Laboratory Tests

    In addition to diabetes tests listed above, used for screening, diagnosing and monitoring, a few other tests may be used in the evaluation of type 1 diabetes:

    • Diabetes autoantibodies – this test may help distinguish between type 1 and type 2 diabetes if the diagnosis is unclear. The presence of one or more of these antibodies indicates type 1 diabetes.
    • Insulin, C-peptide – to monitor insulin production
    • Urine and/or blood ketone tests may be ordered to monitor people who present at the emergency room with symptoms suggesting acute hyperglycemia and to monitor those who are being treated for ketoacidosis. A build up of ketones can occur whenever there is a decrease in the amount or effectiveness of insulin in the body.
       

    Treatment

    There is currently no cure for type 1 diabetes, although there has been some limited success with islet (beta) cell transplantations as a way to potentially restore insulin production.

    Diabetic treatment at the time of diagnosis is somewhat different than ongoing treatment. Type 1 diabetics are sometimes diagnosed when symptoms are acute, with very high blood glucose levels, electrolytes out of balance, and in a state of diabetic ketoacidosis with some degree of dehydration affecting the function of the kidneys. In a worst case scenario, a person may have become unconscious and comatose. This is a life-threatening condition requiring immediate hospitalization and expert care to get the person's body back to its normal balance.

    Ongoing treatment of type 1 diabetes revolves around daily glucose monitoring and control, eating a healthy planned diet, and exercising regularly. Regular exercise lowers blood glucose, increases the body's sensitivity to insulin, and increases circulation.

    Type 1 diabetics must self-check their glucose levels and inject themselves with insulin several times a day. As an alternative, a number of type 1 diabetics have turned to wearing insulin pumps, programmable devices that are carried at the waist and provide small amounts of insulin (through a needle under the skin) throughout the day to more closely match normal insulin secretion The amount and type of insulin administered must be adjusted to take into account what the person is eating, the size of their meals, and the amount of activity they are getting. There are several types of insulin available; some are fast-acting and short-lived while others take longer to act but have a longer duration.

    Most type 1 diabetics use a combination of insulins to meet their needs, and maintaining control can sometimes be a challenge. Stress, illnesses, and infections can alter the amount of insulin necessary, and some type 1 diabetics have "brittle" control: their glucose levels make rapid swings during the day. As another complicating factor, type 1 diabetics may develop antibodies to insulin over time; their body begins to identify the injections as an "intruder" and works to destroy the insulin, resulting in the necessity of higher doses of insulin or of switching to a different kind.

    Type 1 diabetics may also "overshoot," running into trouble with low glucose levels if they inject too much insulin, go extended periods of time without eating, or if their needs change unexpectedly. They must carry glucose with them, in the form of tablets or candy, and be ready to take some at the first signs of low blood sugar (hypoglycemia). Carrying glucagon injections (which stimulate the liver to release glucose) is also recommended for times when a person's hypoglycemia is not responding to oral glucose or for someone else to give them if the person has become unconscious. Acute conditions, such as diabetic ketoacidosis or kidney failure, may require hospitalization to resolve.

  • Type 2 diabetes

    Type 2 diabetes used to be known as non-insulin dependent diabetes or adult onset diabetes. Those affected may produce insulin, but it is either not in a sufficient amount to meet their needs or their body has become resistant to its effects. At the time of diagnosis, people with type 2 diabetes will frequently have both high glucose levels and high insulin levels, but they may not have any symptoms. About 90-95% of diabetes cases in the United States are type 2. It generally occurs later in life, in those who are obese, sedentary, and over 45 years of age. Factors associated with type 2 diabetes include:

    Since Americans are becoming more obese and not getting enough regular exercise, the number of those diagnosed with type 2 diabetes is continuing to rise and it is developing at younger ages.

    The American Diabetes Association (ADA) and the United States Preventive Services Task Force recommend screening for adults age 45 and older and for adults who are under 45 years of age who are overweight and have any additional risk factors for type 2 diabetes. The ADA also recommends that children who are overweight and have two or more risk factors should be considered for diabetes screening.

    Signs and Symptoms

    People with type 2 diabetes may or may not have any noticeable signs or symptoms at the time of diagnosis. The signs and symptoms may be subtle at first and then worsen if the condition is not diagnosed and treated. See the section on Signs and Symptoms for detailed descriptions.

    Laboratory Tests

    In addition to diabetes tests listed above, used for screening, diagnosing and monitoring, a few other tests may be used in the evaluation of type 2 diabetes:

    • Diabetes autoantibodies – this test may help distinguish between type 1 and type 2 diabetes if the diagnosis is unclear. The presence of one or more of these antibodies indicates type 1 diabetes.
    • Insulin, C-peptide – to monitor insulin production
    • Urine and/or blood ketone tests may be ordered to monitor people who present at the emergency room with symptoms suggesting acute hyperglycemia and to monitor those who are being treated for ketoacidosis. A build up of ketones can occur whenever there is a decrease in the amount or effectiveness of insulin in the body.
       

    Prevention and Treatment

    The risk of having type 2 diabetes can be greatly decreased by losing excess weight, exercising, and eating a healthy diet with limited fat intake. By identifying pre-diabetic conditions and making the necessary lifestyle changes to lower glucose levels to normal levels, it may be possible to prevent type 2 diabetes or delay its onset by several years. Normalizing blood glucose can also minimize or prevent damage to veins, arteries and kidneys.

    Type 2 diabetics usually self-check their glucose one or more times a day. Type 2 diabetics are on a continuum, ranging from those who can control their glucose levels with diet and exercise, to those who can take oral medications, to those who need to take daily insulin injections. Many will move along the continuum as their disease progresses.

    The oral medications available fall into three classes. They include drugs that:

    • Stimulate the pancreas to produce more insulin
    • Help make the body more sensitive to the insulin it is producing
    • Slow the absorption of carbohydrates in the stomach (slowing down the post-meal increase in blood glucose)
    • Block glucose from being reabsorbed from the urine by the kidneys
       

    Type 2 diabetics often take two or more of these medications and/or insulin injections, whatever it takes to achieve glucose control.

    Type 2 diabetics may occasionally encounter serious complications if they have ignored initial symptoms, if they have neglected their ongoing treatment, or if they have a serious stress to their system such as a heart attack or stroke or a severe infection. The effects of very high blood glucose levels and dehydration can be cumulative, leading to weakness, confusion, and in severe cases, to convulsions and coma that require immediate hospitalization.

  • Gestational diabetes

    Gestational diabetesis a form of high blood glucose (hyperglycemia) seen in some pregnant women, usually late in their pregnancy. The cause is unknown, but it is thought that some hormones from the placenta increase insulin resistance in the mother, causing elevated blood glucose levels. Those at an increased risk include women who:

    • Are overweight
    • Have had gestational diabetes with a previous pregnancy
    • Are older than 25 years
    • Have previously had a very large baby or have had a stillbirth
    • Have a close relative who has diabetes
    • Have polycystic ovary syndrome (PCOS)
    • Are of African American, Hispanic American, Native American, Asian American, or Pacific Islander ethnicity
       

    Most women are screened for gestational diabetes between their 24th and 28th week of pregnancy. If gestational diabetes is found and not addressed, the baby is likely to be larger than normal, be born with low glucose levels, and be born prematurely. It can also cause complications such as high blood pressure and pre-eclampsia in the pregnant woman.

    The hyperglycemia associated with gestational diabetes usually goes away after the baby's birth, but both the women diagnosed with gestational diabetes and their babies are at an increased risk of eventually developing type 2 diabetes. A woman who has gestational diabetes with one pregnancy will frequently experience it with subsequent pregnancies.

    Signs and Symptoms

    Signs and symptoms of gestational diabetes correspond to those of diabetes in general (see the section on Signs and Symptoms). Some women with gestational diabetes may not have any noticeable symptoms and may be unaware that they have developed the condition.

    Laboratory Tests

    Most professional organizations recommend screening pregnant women for gestational diabetes with a blood test at 24-28 weeks of pregnancy. The American Diabetes Association recommends that pregnant women not previously known to have diabetes be screened and diagnosed, using either a one-step or two-step approach. The American College of Obstetricians and Gynecologists recommends the two-step approach.

    • One-step approach:
      • Perform an oral glucose tolerance test (OGTT). After a fasting glucose level is measured, a woman is given a 75-gram dose of glucose to drink and her glucose levels are measured at 1 hour and 2 hours after the dose. Only one of the values needs to be above a cutoff value for diagnosis:

         
      Time of Sample Collection Glucose Result
      Fasting Equal to or greater than 92 mg/dL (5.1 mmol/L)
      1 hour after glucose drink Equal to or greater than 180 mg/dL (10.0 mmol/L)
      2 hours after glucose drink Equal to or greater than 153 mg/dL (8.5 mmol/L)

       
    • Two-step approach:
      • Perform a glucose challenge test as a screen. A woman is given a 50-gram glucose dose to drink and her blood glucose level is measured after 1 hour. A value of 140 mg/dL (7.8 mmol/L) or greater (or some experts recommend a cutoff of 130 mg/dL (7.2 mmol/L)) is abnormal and indicates the need for a 3-hour OGTT (see below).
      • If the challenge test is abnormal, perform a 3-hour OGTT. After a woman's fasting glucose level is measured, she is given a 100-gram glucose dose and her glucose level is measured at timed intervals. If at least two of the glucose levels at fasting, 1 hour, 2 hour, or 3 hour are above a certain level, then a diagnosis of gestational diabetes is made.

         
      Time of Sample Collection Target Levels**
      (**some labs may use different numbers)
      Fasting (prior to glucose load) 95 mg/dL (5.3 mmol/L)
      1 hour after glucose load 180 mg/dL (10.0 mmol/L)
      2 hours after glucose load 155 mg/dL (8.6 mmol/L)
      3 hours after glucose load 140 mg/dL (7.8 mmol/L)

    Women who are diagnosed with gestational diabetes should be tested at 6-12 weeks after they have delivered their baby to screen for persistent diabetes. This can be done with one of the following:

    • A fasting blood glucose
    • A 2-hour oral glucose tolerance test (OGTT)
    • An A1c test
       

    Treatment

    With gestational diabetes, the mother-to-be will need to eat a modified diet, get regular exercise, and monitor glucose levels as often as her health practitioner suggests. If more control is needed, she will be given insulin injections. At this time, oral medications are not commonly used.

    Usually, the diabetic state resolves after the birth of the baby, although the woman remains at a higher risk of becoming a type 2 diabetic and she should be carefully monitored with any subsequent pregnancies. Right after birth, her baby will be monitored for signs of low blood glucose (hypoglycemia) and for any trouble breathing (respiratory distress).

  • Prediabetes

    Prediabetes, often referred to as impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), is characterized by glucose levels that are higher than normal but not high enough to be diagnostic of diabetes. Recent data from the Centers for Disease Control and Prevention suggest that an estimated 86 million adults in the U.S. had prediabetes in 2012. Usually those who have prediabetes do not have any symptoms but if nothing is done to lower their glucose levels, they are at an increased risk of developing diabetes within about 10 years.

    The American Diabetes Association (ADA) and the United States Preventive Services Task Force recommend diabetes screening for adults age 45 and older and for adults who are under 45 years of age, overweight, and have any additional risk factors for type 2 diabetes.

    Risk factors include:

    • Being overweight, obese, or physically inactive
    • Having a close (first degree) relative with diabetes
    • Being a woman who delivered a baby weighing more than 9 pounds or with a history of gestational diabetes
    • Being a woman with polycystic ovary syndrome (PCOS)
    • Being of a high-risk race or ethnicity such as African American, Latino, Native American, Asian American, Pacific Islander
    • Having high blood pressure (hypertension) or taking medication for high blood pressure
    • Having a low HDL cholesterol level (less than 35 mg/dL or 0.90 mmol/L and/or a high triglyceride level (more than 250 mg/dL or 2.82 mmol/L)
    • Having an A1C equal to or above 5.7% or prediabetes identified by previous testing
    • Having a history of cardiovascular disease (CVD)
       

    The ADA also recommends that children who are overweight and have two or more risk factors should be considered for diabetes screening. If prediabetes is detected, then yearly follow-up testing is recommended.

    Signs and Symptoms

    Those with prediabetes will not have any signs or symptoms at the time of diagnosis.

    Laboratory Tests

    Screening and diagnostic tests are the same as those used for type 2 diabetes (see the Tests section).

    Monitoring is not generally indicated, but the ADA recommends that people with prediabetes be screened for the development of diabetes on a yearly basis.

    Treatment

    The primary focus of treatment for prediabetes and prevention of progression to type 2 diabetes is lifestyle changes. Weight loss, eating a healthy diet, and regular physical activity can help prevent or delay the development of type 2 diabetes and reduce blood glucose levels. In some cases, oral diabetes medications may also be prescribed.

  • Other types

    There are a variety of less common causes of diabetes. Any condition that damages the pancreas and/or affects insulin production or usage can lead to the development of diabetes.

    Latent autoimmune diabetes in adults (LADA or sometimes called diabetes type 1.5) is a slowly progressing type 1 diabetes that is often misdiagnosed as type 2 diabetes. Those who have it tend to produce some of their own insulin when first diagnosed and most have diabetes autoantibodies.

    Monogenic diabetes is a group of causes associated with faulty genes that affect the body's ability to produce insulin:

    • MODY – Maturity onset diabetes of the young is a type of diabetes that is caused by a gene mutation. Several different genes that affect the production of insulin are grouped under MODY. This is an inherited cause of diabetes that is typically detected in children or adolescents, but some people develop it later and some do not develop diabetes.
    • NDM – Neonatal diabetes mellitus is a rare type found in newborns and young infants.
       

    Conditions that block or damage the pancreas can lead to the development of diabetes. Examples include:

    • Cystic fibrosis produces thick mucus that can block the release of pancreatic enzymes and damage the pancreas.
    • Hemochromatosis is an inherited condition associated with increased iron storage. Iron buildup can damage the pancreas and other organs. It is sometimes referred to as "bronze diabetes" because the excess iron can turn a person's skin a bronze color.
    • Pancreatitis, pancreatic cancer, and other pancreatic diseases that damage the pancreas and/or beta cell production
    • Pancreas trauma or removal
       

    Signs and Symptoms

    Signs and symptoms of these causes of diabetes correspond to those of diabetes in general. See the section on Signs and Symptoms for detailed information. There may also be additional symptoms linked to specific underlying conditions, such as hemochromatosis and cystic fibrosis.

    Laboratory Tests

    In addition to diabetes tests listed above, used for screening, diagnosing and monitoring, a few other tests may be used in the evaluation of other types and causes of diabetes:

    • Diabetes autoantibodies – this test may help detect LADA and distinguish it from type 2 diabetes if the diagnosis is unclear.
    • Genetic testing may be performed to detect the specific gene mutation associated with MODY or NDM. In some cases, family members may also be tested to determine if they have inherited the same altered gene.
    • Testing to detect other conditions that may cause diabetes is usually done separately. There is an awareness that these conditions are associated with an increased risk for the development of diabetes.
       

    Treatment

    People who have underlying conditions will need to be treated for these conditions, in addition to diabetes treatment.

    Most of these cases of diabetes are not preventable, but maintaining a healthy diet and lifestyle, managing underlying conditions, and normalizing blood glucose can help minimize or prevent further pancreas damage and vascular and kidney damage.

    Those affected may need to self-check their glucose several times a day. Each case will be different, and a person's needs are likely to change over time. Some people may be able to control their glucose levels with diet and exercise, some may need oral medications, and others may need to take daily insulin injections. People often move along a treatment continuum as their disease progresses. The goals are to preserve beta cell function and insulin production, if possible, and to achieve and maintain glucose control.

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

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(Updated 2014 September 10). Diagnosis of Diabetes and Prediabetes. National Diabetes Information Clearinghouse [On-line information]. Available online at http://diabetes.niddk.nih.gov/dm/pubs/diagnosis/ through http://diabetes.niddk.nih.gov. Accessed September 2014.

(Updated 2014 August 27). Monogenic Forms of Diabetes: Neonatal Diabetes Mellitus and Maturity-onset Diabetes of the Young. National Diabetes Information Clearinghouse [On-line information]. Available online at http://diabetes.niddk.nih.gov/dm/pubs/mody/index.aspx through http://diabetes.niddk.nih.gov. Accessed September 2014.

Parkin, C. (2013 February). LADA, the Other Diabetes, Can Be Hard to Spot. Diabetes Forecast [On-line information]. Available online at http://www.diabetesforecast.org/2013/feb/lada-the-other-diabetes-can-be-hard-to-spot.html through http://www.diabetesforecast.org. Accessed September 2014.

(2013 September). Gestational Diabetes: What You Need to Know. National Diabetes Information Clearinghouse [On-line information]. Available online at http://www.diabetes.niddk.nih.gov/dm/pubs/gestational_ES/ through http://www.diabetes.niddk.nih.gov. Accessed September 2014.

(2014 January). Standards of Medical Care in Diabetes 2014. Diabetes Care Volume 37, Supplement 1 [On-line information]. Available online at http://care.diabetesjournals.org/content/37/Supplement_1/S14.full.pdf+html through http://care.diabetesjournals.org. Accessed September 2014.

(2014 January). Diagnosis and Classification of Diabetes Mellitus. Diabetes Care Volume 37, Supplement 1 [On-line information]. Available online at http://care.diabetesjournals.org/content/37/Supplement_1/S81.full.pdf+html through http://care.diabetesjournals.org. Accessed September 2014.

(2013 September). Gestational Diabetes. American College of Obstetricians and Gynecologists [On-line information]. Available online at http://www.acog.org/Patients/FAQs/Gestational-Diabetes through http://www.acog.org. Accessed September 2014.

Copeland, K. et. al. (2013 January 28). Management of Newly Diagnosed Type 2 Diabetes Mellitus (T2DM) in Children and Adolescents. Pediatrics v 131 (2) [On-line information]. Available online at http://pediatrics.aappublications.org/content/131/2/364.full?sid=d1840c80-287b-43ca-ac9c-68b0b1d5dfa8 through http://pediatrics.aappublications.org. Accessed September 2014.

(Reviewed 2013 August 2). Hemochromatosis. American Diabetes Association [On-line information]. Available online at http://www.diabetes.org/living-with-diabetes/complications/related-conditions/hemochromatosis.html through http://www.diabetes.org. Accessed September 2014.

Gebel, E. (2010 May). Another Kind of Diabetes: MODY, Often misdiagnosed, the disease is caused by a faulty gene. Diabetes Forecast [On-line information]. Available online at http://www.diabetesforecast.org/2010/may/another-kind-of-diabetes-mody.html through http://www.diabetesforecast.org. Accessed September 2014.

Gebel, E. (2010 May). The Other Diabetes: LADA, or Type 1.5, Latent autoimmune diabetes in adults is gradually being understood. Diabetes Forecast [On-line information]. Available online at http://www.diabetesforecast.org/2010/may/the-other-diabetes-lada-or-type-1-5.html through http://www.diabetesforecast.org. Accessed September 2014.

(2014 July). Overview of Diabetes in Children and Adolescents. From the National Diabetes Education Program [On-line information]. Available online at http://ndep.nih.gov/media/Overview-of-Diabetes-Children-508_2014.pdf through http://ndep.nih.gov. Accessed September 2014.

(October 2014) U.S. Preventive Services Task Force. Draft Recommendation Statement. Abnormal Glucose and Type 2 Diabetes Mellitus in Adults: Screening. Available online at http://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementDraft/screening-for-abnormal-glucose-and-type-2-diabetes-mellitus through http://www.uspreventiveservicestaskforce.org. Accessed November 22, 2014.

July 25, 2013. Lisa Nainggolan. ACOG Issues New Practice Bulletin on Gestational Diabetes. Medscape News. Available online at http://www.medscape.com/viewarticle/808409 through http://www.medscape.com. Accessed October 29.

July 01, 2014. Brown, HL. ACOG Guidelines at a Glance: Gestational Diabetes. Available online at http://contemporaryobgyn.modernmedicine.com/contemporary-obgyn/content/tags/acog-guidelines/acog-guidelines-glance-gestational-diabetes-mellitus through http://contemporaryobgyn.modernmedicine.com. Accessed October 2014.

Soures Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

(1995-2004). Diabetes Mellitus. The Merck Manual of Medical Information-Second Home Edition [On-line information]. Available online at http://www.merck.com/mmhe/sec13/ch165/ch165a.html?qt=Diabetes&alt=sh through http://www.merck.com.

(2005 January). Diagnosis of Diabetes. National Diabetes Information Clearinghouse, NIH Publication No. 05-4642 [On-line information]. Available online at http://diabetes.niddk.nih.gov/dm/pubs/diagnosis/index.htm through http://diabetes.niddk.nih.gov. Reaccessed 2/20/08.

All About Diabetes. American Diabetes Association [On-line information]. Available online at http://www.diabetes.org/about-diabetes.jsp through http://www.diabetes.org. Reaccessed 2/20/08.

National Diabetes Fact Sheet. Centers for Disease Control [On-line information]. Available online at http://www.cdc.gov/diabetes/pubs/factsheet.htm through http://www.cdc.gov.

Jonnalagadda, S. (2004 February 19). Serum ketones. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003498.htm.

Magee, C. (2005 December 9, Updated). Ketones – urine. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003585.htm.

(2003). Ketone testing. National Academy of Clinical Biochemistry, Laboratory Medicine Practice Guidelines [On-line information]. PDF available for download at http://www.nacb.org/lmpg/diabetes/5_diabetes_keytone.pdf#search='%2C%20ketone%20diabetes' through http://www.nacb.org.

National Diabetes Information Clearinghouse: National Diabetes Statistics (2005). Available online at http://diabetes.niddk.nih.gov/dm/pubs/statistics/ through http://diabetes.niddk.nih.gov.

U.S. Preventive Services Task Force. Recommendations and Rationale: Screening for Gestational Diabetes Mellitus (February 2003). Available online at http://www.ahrq.gov/clinic/3rduspstf/gdm/gdmrr.htm through http://www.ahrq.gov.

American Diabetes Association. Executive summary: standards of medical care in diabetes—2010. Jan 2010. Diabetes Care 33: S4-S10.

(January 2010) The Endocrine Society Statement on the use of A1c for Diabetes Diagnosis and Risk Estimation. PDF available for download at http://www.endo-society.org/advocacy/upload/TES-Statement-on-A1C-Use.pdf through http://www.endo-society.org. Accessed January 2010.

(Updated 2011 May 5). Basics about Diabetes. Centers for Disease Control and Prevention [On-line information]. Available online at http://www.cdc.gov/diabetes/consumer/learn.htm through http://www.cdc.gov. Accessed May 2011.

(2011). National Diabetes Fact Sheet, 2011. CDC [On-line information]. PDF available for download at http://www.cdc.gov/diabetes/pubs/pdf/ndfs_2011.pdf through http://www.cdc.gov. Accessed May 2011.

(Updated 2010 October). Type 2 Diabetes Fact Sheet. National Institutes of Health [On-line information]. Available online at http://report.nih.gov/NIHfactsheets/Pdfs/Type2Diabetes(NIDDK).pdf through http://report.nih.gov. Accessed May 2011.

Khardori, R. (Updated 2011 May 19). Type 2 Diabetes Mellitus. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/117853-overview through http://emedicine.medscape.com. Accessed May 2011.

Moore, T. (Updated 2011 April 13). Diabetes Mellitus and Pregnancy. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/127547-overview through http://emedicine.medscape.com. Accessed May 2011.

Mayo Clinic Staff (2011 March 9). Diabetes. MayoClinic.com [On-line information]. Available online at http://www.mayoclinic.com/health/diabetes/DS01121/METHOD=print through http://www.mayoclinic.com. Accessed May 2011.

Grenache, D. (Updated 2011 April). Diabetes Mellitus. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/DiabetesMellitus.html#tabs=0 through http://www.arupconsult.com. Accessed May 2011.

Kerr, M. (Updated 2009 June 23) ADA 2009: New Blood Test Bridges Time Gap Between Serum Glucose and Hemoglobin A1c. Medscape Medical News [On-line information]. Available online at http://www.medscape.com/viewarticle/704358 through http://www.medscape.com. Accessed May 2011.

American Diabetes Association. Standards of Medical Care in Diabetes—2011. Diabetes Care January 2011 34:S11-S61. Available online at http://care.diabetesjournals.org/content/34/Supplement_1/S11.full through http://care.diabetesjournals.org

Metzger BE, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care 2010; 33: 676-82.