Screening Tests for Teens (Ages 13-18)

Beginning in childhood, the waxy substance called cholesterol and other fatty substances known as lipids begin to build up in the arteries, hardening into plaques that narrow the arterial passageways. During adulthood, plaque buildup and resulting health problems occur not only in the arteries supplying blood to the heart muscle but in arteries throughout the body (a problem known as atherosclerosis). For both men and women in the United States, the number one cause of death is heart disease, and the amount of cholesterol in the blood greatly affects a person's chances of suffering from it.

Growing evidence shows that the biological processes that precede heart attacks and cardiovascular disease begin in childhood, although they don't generally cause symptoms or lead to disease until middle age or later. Experts encourage physical activity and healthy eating in childhood and adolescence, limiting saturated fat and trans fat, to help protect against heart disease in adulthood.

Monitoring and maintaining healthy levels of cholesterol are important in staying healthy. Screening for high cholesterol, typically with a lipid profile, is important because there are usually no symptoms. A lipid profile usually includes total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Non-HDL-cholesterol can also be calculated by subtracting the HDL-C value from the total cholesterol result. Typically, fasting for 9-12 hours before having the blood sample drawn is required; only water is permitted. However, some laboratories offer non-fasting lipid profiles. In particular, children and teens may have testing done without fasting.

Since screening recommendations are not always consistent between healthcare organizations, it's important to work with your children's healthcare provider to develop a cholesterol-screening plan that is right for them.

Recommendations

• The American Academy of Pediatrics (AAP) recommends routine lipid testing in all youths once between the ages of 9 and 11 and again between 17 and 21. Testing at a younger age and more frequent screening with a lipid profile is recommended for youths who are at an increased risk of developing heart disease as adults. Children younger than 2 years old are too young to be tested.
• The American Heart Association (AHA) does not recommend routine screening for children and adolescents with normal heart disease risk.
• The U.S. Preventive Services Task Force (USPSTF) recommends screening for high cholesterol in youths 20 and younger only if they are at increased risk. Currently, there is not enough evidence to recommend for or against routine screening in all youths, according to the Task Force.

Risk Factors

• Family History: Youths are at increased risk if they have a parent, grandparent, aunt/uncle, or sibling who has high cholesterol or if they have a family history of cardiovascular disease (prior to age 55 in male relative and age 65 in female relative).
• Personal Health: Youths are also at higher risk if they:
  • Are overweight or obese
  • Have a diet high in fats, especially saturated or trans fat
  • Get little or no exercise
  • Have diabetes or hypertension (high blood pressure)
  • Smoke cigarettes or use other tobacco products

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Links
American Heart Association: Hey Kids, Learn About Cholesterol
KidsHealth.org: Cholesterol 

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Sources Used in Current Review (last reviewed 7/12/17)

(2016 August 9). Screening for lipid disorders in children and adolescents. U.S. Preventive Task Force recommendation statement. U.S. Preventive Services Task Force. Available online at http://jamanetwork.com/journals/jama/fullarticle/2542642. Accessed June 2017.

Swift, D. (2017 February 17). AAP updates preventive care guidelines, targets HIV, depression screening. Medscape, News and Perspective. Available online at http://www.medscape.com/viewarticle/875950?pa=gzilco%2FMqWtheZwS%2BIv9ew%2F1apM1lJZswxmtf97%2BKCThPQZnAFNU5cYUCO0MrUVvVrJxKJt4DRD8mxYr6kYfOw%3D%3D. Accessed June 2017.

(Reviewed 2017 April). Common misconceptions about cholesterol. American Heart Association. Available online at http://www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/Common-Misconceptions-about-Cholesterol_UCM_305638_Article.jsp#.WUsgzhPyvR0. Accessed June 2017.

(Reviewed 2017 April). How to get your cholesterol tested. American Heart Association. Available online at http://www.heart.org/HEARTORG/Conditions/Cholesterol/HowToGetYourCholesterolTested/How-To-Get-Your-Cholesterol-Tested_UCM_305595_Article.jsp#.WUrsWxPyvEY. Accessed June 2017.

@2017. Periodicity schedule. American Academy of Pediatrics. Available online at https://www.aap.org/en-us/professional-resources/practice-transformation/managing-patients/Pages/Periodicity-Schedule.aspx. Accessed June 2017.

Family History of Early Atherosclerotic Cardiovascular Disease. National Heart, Lung and Blood Institute. Available online at https://www.nhlbi.nih.gov/health-pro/guidelines/current/cardiovascular-health-pediatric-guidelines/full-report-chapter-4. Accessed June 2017.

About 193,000 children and adolescents under 20 years of age in the United States had diabetes in 2015, according to the U.S. Centers for Disease Control and Prevention (CDC). While most cases of type 1 diabetes are diagnosed in those under the age of 18, the signs and symptoms often develop rapidly and the diagnosis is often made in an emergency room setting. Thirty percent of new-onset cases of type 1 diabetes in children present with diabetic ketoacidosis. Thus, blood glucose measurement as screening for type 1 diabetes in asymptomatic teens is presently not necessary. On the other hand, some youth with type 2 diabetes will have no obvious signs or symptoms of high blood glucose, especially early in the disease, and screening can be a useful tool. The incidence of type 2 diabetes has increased dramatically in the last decade, especially in minority populations, according to the American Diabetes Association (ADA).

Developing the disease early in life means that the patient is at increased risk for the development of diabetic complications because of the potentially prolonged duration of exposure to high blood glucose (hyperglycemia). This increases the risk of serious health problems earlier in adulthood, such as heart disease, kidney failure, blindness, and foot amputations.

Risk Factors
Overweight, obesity, and physical inactivity are all contributing factors to development of type 2 diabetes, and they too have become national health problems. As public health experts work to educate Americans on how to avoid diabetes and its serious complications, parents and teens should be aware that healthy eating habits and activity choices can lower an individual's risk of developing type 2 diabetes and related complications later in life.

A youth who is overweight—defined as [1] a body mass index (BMI) greater than the 85th percentile for age and sex, [2] weight for height greater than the 85th percentile, or [3] overweight more than 120% of ideal for height— plus 2 other known risk factors faces a substantial risk of having or developing type 2 diabetes, warns the ADA. These risk factors include:

• Having a close relative with type 2 diabetes
• Being Native American, African American, Latino, Asian American, or Pacific Islander
• Having signs of or conditions associated with insulin resistance, including acanthosis nigricans, high blood pressure (hypertension), unhealthy lipid levels (dyslipidemia), polycystic ovary syndrome, or having a reduced birth weight (small-for-gestational age)
• Having a birth mother who has diabetes or had gestational diabetes

Recommendations
The ADA makes the following screening recommendations:

• Consider screening overweight adolescents who have 2 or more risk factors for diabetes every 3 years, starting at 10 years of age or at the onset of puberty
• Screen using one of the following tests:
  • Fasting glucose (fasting blood glucose, FBG) – this test measures the level of glucose in the blood after an 8-12 hour fast.
  • Hemoglobin A1c (also called A1c or glycated hemoglobin) – this test evaluates the average amount of glucose in the blood over the last 2 to 3 months and has been recommended as another test to screen for diabetes.
  • 2-hour oral glucose tolerance test (OGTT) – this test involves drawing a fasting blood blood sample for glucose measurement, followed by having the person drink a solution containing 1.75 grams of glucose per kilogram body weight to a maximum of 75 grams and then drawing another sample two hours after the person begins to consume the glucose solutions.

If any of these results is abnormal, the test is repeated on another day. If the repeat result is also abnormal, a diagnosis of diabetes is made.

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Links
KidsHealth.org: Teens – Diabetes Center
American Diabetes Association
American Diabetes Association: Be Healthy Today; Be Healthy For Life, Information for Youth and their Families, Living with Type 2 Diabetes 

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Sources Used in Current Review (last reviewed 9/18/17)

(2017). National diabetes Statistics Report, 2017. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf. Accessed on 8/06/17.

(2015 October). Abnormal Blood Glucose and Type 2 Diabetes Mellitis: Screening. U.S. Preventive Services Task Force. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/screening-for-abnormal-blood-glucose-and-type-2-diabetes?ds=1&s=diabetes. Accessed on 8/06/17.

(2017 July 27, Updated). What’s New in Diabetes. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/new/index.html. Accessed on 8/06/17.

(2017 July 25, Updated). Who’s at Risk? Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/diabetes/basics/risk-factors.html. Accessed on 8/06/17.

Genzen, J. et. al. (2017 July, Updated). Diabetes Mellitus. ARUP Consult. Available online at https://arupconsult.com/content/diabetes-mellitus. Accessed on 8/06/17.

(2016 November). Diabetes Tests & Diagnosis. National Institute of Diabetes and Digestive and Kidney Diseases. Available online at https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis. Accessed on 8/06/17.

(2015). Screening and Monitoring of Prediabetes. American Association of Clinical Endocrinologists. Available online at http://outpatient.aace.com/prediabetes/screening-and-monitoring-prediabetes. Accessed on 8/06/17.

Diabetes Management Guidelines, American Diabetes Association (ADA) 2016 Guidelines. National Diabetes Education Initiative. Available online at http://www.ndei.org/ADA-2013-Guidelines-Criteria-Diabetes-Diagnosis.aspx.html#children. Accessed on 8/06/17.

Childhood obesity is a growing problem in the United States. About 17% of children and adolescents in the U.S. are obese, and at least three out of four obese teens grow up to become obese adults. There are many serious health consequences of being obese, including increased risk of developing type 2 diabetes, high blood pressure and high cholesterol, joint problems, sleep apnea, and social and psychological problems. Those who continue to be overweight into adulthood are at greater risk for serious health problems, including heart disease, stroke, and some cancers.

Recommendations

The American Academy of Pediatrics (AAP) recommends routine obesity screening of children. At least once a year, a healthcare practitioner should assess a child's weight status. This is the recommendation of a federally-convened expert committee, one that represents 15 national healthcare organizations, including AAP. The child's weight and height as well as age and sex are considered in determining their body mass index (BMI) percentile. BMI is a useful tool for estimating body fat.

• Overweight: An overweight youth (one whose BMI is between the 85th percentile and the 94th percentile on standardized growth charts) faces additional health risks.
• Obese: An obese youth (at or above the 95th percentile on standardized growth charts or a BMI of greater than or equal to 30 kg/m2, whichever is lower) faces even more serious health risks.

For children aged 2 years and older, AAP says BMI changes should be monitored by calculating and plotting BMI on the Centers for Disease Control and Prevention (CDC) growth charts at every healthcare visit so that interventions can be implemented when a child starts to cross BMI percentiles upward, even before he or she approaches the 85th or the 95th percentile.

The U.S. Preventive Services Task Force (USPSTF) recommends that clinicians screen children, including adolescents, ages 6 and older for obesity and refer them to programs to promote improvements in weight status. The Task Force has found that the BMI is an acceptable measure for determining excess weight and defines "overweight" and "obese" as above. The American Academy of Family Physicians makes the same recommendation.

At each well visit, the following should be discussed: the teen's dietary patterns, levels of physical activity, and sedentary behaviors. The family's history of obesity, type 2 diabetes, and high blood pressure are important considerations as are a number of other physical measurements the healthcare provider can take. The goal is to prevent and address the problems of overweight and obesity through identification and early interventions, namely, changes to diet and exercise, to achieve a healthy weight and BMI.

Children's body mass calculations need to be related to their growth charts. A visit to a healthcare practitioner will provide you with the most reliable information, but the calculator on the CDC web site (in Links below) can help you determine if your teen is at risk of being overweight.

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Links
HealthyChildren.org: Obesity  
Centers for Disease Control and Prevention: BMI Percentile Calculator for Child and Teen 

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Sources Used in Current Review

Centers for Disease Control and Prevention. Childhood Obesity Facts. Available online at https://www.cdc.gov/obesity/data/childhood.html. Accessed October 2016.

U.S. Preventive Services Task Force. Obesity in Children and Adolescents: Screening. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryDraft/obesity-in-children-and-adolescents-screening1?ds=1&s=child%20obesity%20screening. Accessed October 2016.

American Academy of Pediatrics. Press Room: AAP Updates Recommendations on Obesity Prevention. Available online through https://www.aap.org. Accessed October 2016.

Daniels, Stephen R. and Hassink, Sandra G. and the Committee on Nutrition. The Role of the Pediatrician in Primary Prevention of Obesity. Pediatrics. July 2015, Vol 136 / Issue 1. Available online at http://pediatrics.aappublications.org/content/136/1/e275. Accessed October 2016.

Herman, Amy Orciari. USPSTF Again Recommends Obesity Screening in Kids, Clarifies Age Group. NEJM Journal Watch. November 2, 2016. Available online at http://www.jwatch.org/fw112212/2016/11/02/uspstf-again-recommends-obesity-screening-kids-clarifies?query=pfwTOC&jwd=000020042086&jspc=. Accessed October 2016.

Blood pressure is the force that your blood puts on your artery walls. High blood pressure, also called hypertension, happens when that force is consistently too high.

About four percent of youths 12-19 years old have high blood pressure, according to the Centers for Disease Control. Another 10% have blood pressure that is above what is considered optimal, but not high enough to diagnose as hypertension.

Detecting and treating high blood pressure is important because it can damage your circulatory system and increases your risk of having a heart attack, stroke, and other health problems later in life. Hypertension contributes to one out of every seven deaths in the U.S. In general, the longer you have high blood pressure, the greater the potential for damage to your heart and other organs including your kidneys, brain, and eyes.

Hypertension is a risk factor for developing serious health problems later in life. So, while high blood pressure risk increases with age, even teenagers should still pay attention to their blood pressure. Hypertension in young people is often linked to obesity.

Most people with high blood pressure aren’t aware of it because there are often no obvious symptoms. The only way to find out if you have high blood pressure is to get tested.

How is blood pressure measured?

Blood pressure was traditionally measured in healthcare settings using a blood pressure cuff with a pressure gauge (sphygmomanometer). This air-filled cuff wraps around the upper arm and obstructs blood flow. By releasing small amounts of air from the cuff, blood slowly flows back into the arm. The pressure measured inside the cuff is the same as the pressure inside the arteries.

There are two numbers measured for blood pressure. Systolic blood pressure is the pressure when your heart beats. Diastolic pressure is when the heart relaxes between beats and the pressure drops. Together, they are written as systolic over diastolic pressure. For instance, a blood pressure of 120/80 mm Hg (millimeters of mercury) corresponds to a systolic pressure of 120 and a diastolic pressure of 80.

Using a sphygmomanometer is still considered the best method but, more commonly, devices that combine a blood pressure cuff with electronic sensors are used to measure blood pressure. Another method is to have you wear a device that monitors and records the blood pressure at regular intervals during the day to evaluate blood pressure over time. This is especially helpful during the diagnostic process and can help rule out "white coat" hypertension, the high measurements that can occur when you are at the doctor's office and not at other times.

A single measurement of blood pressure is not enough to diagnose hypertension. Typically, multiple readings are taken on different days. A diagnosis of high blood pressure is made if measurements are consistently high.

A teen’s blood pressure may vary greatly between healthcare visits, or even within visits. So, it is important to obtain multiple measurements over time before diagnosing and treating children and teens for hypertension.

What is normal blood pressure?

High blood pressure for teens is defined differently than it is in adults. The 2017 American Academy of Pediatrics Clinical Practice Guideline recommends comparing a teen’s blood pressure to tables that take into account what’s normal for healthy youths of the same sex and height class. If a teen has blood pressure higher than 90 to 95 percent of other youths in their age and height class, then they may have high blood pressure.

Risk Factors

Some risk factors for hypertension are especially relevant to teens. These include:

• Tobacco exposure (e.g. smoking cigarettes)
• Obesity
• Not getting enough exercise, inactivity
• Unhealthy diet
   

Some risk factors are related to things you can’t change, such as:

• African American descent
• A family history of high blood pressure
   

Others are lifestyle factors that are under your control including:

• Heavy alcohol drinking
• A diet high in salt
   

Sometimes medication, illegal drug use, or underlying conditions such as diabetes, kidney disease or thyroid disease, can cause hypertension. This is called secondary hypertension and treating these conditions, or stopping the medication, may remove the underlying cause of high blood pressure.

Screening Recommendations

The 2017 American Academy of Pediatrics (AAP) Clinical Practice Guideline, endorsed by the American Heart Association, recommends annual blood pressure measurement for healthy adolescents.

The AAP recommends that adolescents with certain conditions have their blood pressure measured during every healthcare visit. The conditions include:

• Obesity
• Taking medication known to raise blood pressure
• Diabetes
• Kidney disease
• A severe narrowing in the aorta, the major blood vessel carrying oxygenated blood to the body
   

The American Heart Association and American Thoracic Society’s 2015 guidelines on hypertension in children acknowledge that the causes of hypertension in teens are often different from those in adults. They focus on classifying the type of hypertension a teen has and determining treatment.

Related Content

Conditions: Hypertension

Sources (Last Review: 4/17/19)

(Reviewed 2014 July 7). Family History and Other Characteristics That Increase Risk for High Blood Pressure. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/bloodpressure/family_history.htm. Accessed February 2019.

Abman, S. et al. (2015 November 3). Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society. Available online at https://www.ahajournals.org/doi/10.1161/CIR.0000000000000329. Accessed February 2019.

(2015 February 15). Screening for primary hypertension in children and adolescents: recommendation statement. U.S. Preventative Services Task Force. Available online at: https://www.aafp.org/afp/2015/0215/od1.html. Accessed February 2019.

(Reviewed 2016 October 31).High blood pressure in children. The American Heart Association. Available online at https://www.heart.org/en/health-topics/high-blood-pressure/why-high-blood-pressure-is-a-silent-killer/high-blood-pressure-in-children. Accessed February 2019.

(2016 October 31). What is high blood pressure? American Heart Association. Available online at https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure/what-is-high-blood-pressure. Accessed February 2019.

Flynn, J.T. (2017 September). Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. American Academy of Pediatrics. Available online at: http://pediatrics.aappublications.org/content/140/3/e20171904. Accessed February 2019.

(Reviewed 2017 November 13). Monitoring your blood pressure at home. American Heart Association. Available online at https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings/monitoring-your-blood-pressure-at-home. Accessed February 2019.

(Reviewed 2017 November 30). Monitor your blood pressure. American Heart Association. Available online at https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure. Accessed February 2019.

(Reviewed 2017 November 30). Understanding blood pressure readings. American Heart Association. Available online at https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings. Accessed February 2019.

(Reviewed 2018 July 18). High blood pressure during childhood and adolescence. Centers for Disease Control and Prevention. Available online athttps://www.cdc.gov/bloodpressure/youth.htm#cdc. Accessed February 2019.

(© 2019). High blood pressure in children and adolescents. Stanford Children’s Health. Available online at https://www.stanfordchildrens.org/en/topic/default?id=high-blood-pressure-in-children-and-adolescents-90-P01609. Accessed February 2019.

(2019 February 13). High blood pressure. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/bloodpressure/index.htm. Accessed February 2019.

Heart health screenings. American Heart Association. Available online at https://www.heart.org/en/health-topics/consumer-healthcare/what-is-cardiovascular-disease/heart-health-screenings. Accessed February 2019.

Highlights from the 2017 guideline for the prevention, detection, evaluation and management of high blood pressure in adults. American Heart Association. Available online at https://www.heart.org/-/media/data-import/downloadables/hypertension-guideline-highlights-flyer-ucm_497841.pdf. Accessed February 2019.

High blood pressure. National Heart, Lung, and Blood Institute. Available online at https://www.nhlbi.nih.gov/health-topics/high-blood-pressure. Accessed February 2019.

Teens grow and develop rapidly and need iron in their diet to develop normally. If a teen does not consume enough iron, there is a risk of developing iron deficiency. Iron deficiency can cause anemia, a condition that can delay a teen's mental, motor, and behavioral development and create problems that last long after the iron level is raised to a healthy level. Poor motor skills, behavior problems at home and school, and poor performance in school can be the long-term consequences of not receiving enough iron as a child.

Iron deficiency may also be due to a severe blood loss, a genetic disorder, or something interfering with the body's ability to absorb iron, such as a medication the teen is taking or a chronic illness (e.g., celiac disease).

Recommendations
The American Academy of Pediatrics (AAP) recommends teens be screened with a hemoglobin and hematocrit test if they have risk factors for iron deficiency or iron deficiency anemia.

Risk factors for iron deficiency anemia in teens may include:

• Households with a low income or living in poverty
• Poor or restricted diet that doesn't provide enough iron
• Teen girls who begin menstruating can be at risk if they don't consume enough iron
• History of:
  • Medications that interfere with iron absorption
  • Extensive blood loss
  • Exposure to lead

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Link
Mayo Clinic: Iron deficiency in children - Prevention tips for parents 

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Sources Used in Current Review

American Academy of Pediatrics. Policy Statement: 2014 Recommendations for Pediatric Preventive Health Care. Pediatrics. Available online at http://pediatrics.aappublications.org/content/pediatrics/133/3/568.full.pdf. Accessed October 2016.

Chlamydia and gonorrhea are the most common bacterial sexually transmitted diseases (STDs) in the United States today, but many infected people have no symptoms. These infections usually affect the genitals but may also cause infections of other areas, such as the throat and rectum. Pregnant women may transmit the infections to their newborns. Left untreated, these diseases can cause infertility and other health complications. However, both diseases can be cured with antibiotics.

In the United States, reported rates of chlamydia and gonorrhea are highest among adolescent girls (15-19 years of age) and young women (20-24 years old). However, any sexually active person can get infected with chlamydia or gonorrhea. Many people have both infections at the same time.

Recommendations for Adolescent Girls
The U.S. Centers for Disease Control and Prevention (CDC), the U.S. Preventive Services Task Force (USPSTF), the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG) recommend that:all sexually active teen girls have chlamydia and gonorrhea screening. The CDC, AAP and ACOG specifically recommend annual screening.

For screening recommendations during pregnancy, see Pregnancy & Prenatal Testing.

Recommendations for Adolescent Boys

These organizations do not recommend routine screening for sexually active, heterosexual boys. Health care providers may, however, use their judgment and consider risks, such as prevalence of these STDs in the community. It is important to remember that an infected male can spread these diseases and even re-infect a partner if he does not complete treatment. For sexually active males who have sex with other males, the CDC and AAP recommend chlamydia and gonorrhea screening at least annually.

Risk

Sexually active teens face more risk of chlamydia and gonorrhea infection, compared to adults age 25 and older.

Examples of other risk factors include:

• Previous chlamydia or gonorrhea infections, even if you were treated
• Having STDs, especially HIV
• Having new or multiple sex partners
• Having a sex partner diagnosed with an STD
• Using condoms inconsistently
• Exchanging sex for money or drugs
• Using illegal drugs
• Living in a detention facility

Because reinfection rates are high, the CDC recommends that both teen girls and boys who are treated for chlamydia or gonorrhea infection be retested approximately 3 months after treatment or at their next health care visit, regardless of whether they believe that their sex partners were treated. It is important to continue annual screening for these diseases because reinfection is always possible.

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Links

CDC: Get Tested, Find Free, Fast, and Confidential Testing Near You

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Sources Used in Current Review (last reviewed 12/5/17)

(2016 October 17, Updated). Chlamydia - CDC Fact Sheet (Detailed). Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/std/chlamydia/stdfact-chlamydia-detailed.htm. Accessed on October 2017.

(2016 October 28, Updated). Gonorrhea – CDC Fact Sheet (Detailed Version). Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/std/gonorrhea/stdfact-gonorrhea-detailed.htm. Accessed on October 2017.

(2016 December). Chlamydia, Gonorrhea, and Syphilis FAQ. American Congress of Obstetricians and Gynecologists. Available online at https://www.acog.org/Patients/FAQs/Chlamydia-Gonorrhea-and-Syphilis. Accessed on October 2017.

Fisher, M. and Schlaberg, R. (2017 July, Updated). Sexually Transmitted Infections. ARUP Consult. Available online at https://arupconsult.com/content/sexually-transmitted-infections/?tab=tab_item-1. Accessed on October 2017

(December 1, 2016) Centers for Disease Control and Prevention. STD Risk and Oral Sex - CDC Fact Sheet. Available online at https://www.cdc.gov/std/healthcomm/stdfact-stdriskandoralsex.htm. Accessed on October 2017.

(September 2014) US Preventive Services Task Force. Final Recommendation Statement Chlamydia and Gonorrhea: Screening. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/chlamydia-and-gonorrhea-screening. Accessed on October 2017.

HIV is the virus that causes AIDS (acquired immunodeficiency syndrome), a life-threatening disease. Initially, an HIV infection may cause no symptoms or cause non-specific, flu-like symptoms that resolve after a short time period. The only way to determine whether a person has been infected is through HIV testing.

If the infection is not detected and treated, eventually symptoms of AIDS emerge and begin to progressively worsen. Without treatment, HIV destroys the immune system over time and leaves a person's body vulnerable to debilitating infections.

HIV is spread in the following ways:

• By having sex with an infected partner
• By sharing needles or syringes (such as with intravenous injection drug abuse)
• During pregnancy or birth; if a pregnant woman is infected with HIV, the virus can be passed to and infect her developing baby.
• Through contact with infected blood
• In the U.S. today, because of screening blood for transfusion and heat-treating techniques and other treatments of blood derivatives, the risk of getting HIV from transfusions is extremely small. However, before donated blood was screened beginning in 1985 in the U.S. and before treatments were introduced to destroy HIV in some blood products, such as factor 8 and albumin, HIV was transmitted through transfusion of contaminated blood or blood components.

Why Get Screening?
Screening for HIV is now part of routine healthcare in the United States and is an important part of wellness and prevention. This is because diagnosis early in the course of infection leads to timely, effective treatment that decreases the risk of progression to AIDS. A major National Institutes of Health (NIH) clinical trial published in 2015 found that individuals with HIV have a lower risk of developing AIDS and other serious illnesses if they start antiretroviral therapy sooner rather than later.

Early diagnosis also has important benefits for others and society at large. Thousands of people are diagnosed with HIV each year, and about 1 in 8 people in the United States with HIV are unaware that they have it. An individual can prevent further disease spread by learning their status, modifying behavior and not exposing others to infected blood or body fluids. Pregnant women who have HIV can start treatment to prevent spreading the disease to their children.

If an HIV screening test shows a person is not infected, he or she can take steps to avoid infection. For individuals who are HIV-negative but at high risk for HIV, the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) recommend that they consider taking pre-exposure prophylaxis (PrEP), a daily pill to help prevent infection. For people taking PrEP consistently, the risk of HIV infection is significantly lower compared to those who did not take it.

Know Your Risk
Several situations put you at high risk of contracting HIV:

• You've had unprotected sex with more than one partner.
• You have or have had a sexually transmitted disease (STD), which appears to make people more susceptible to and at higher risk for acquiring HIV infection during sex with infected partners.
• You're a man who has had sexual contact with another man.
• You have exchanged sex for money or drugs or had anonymous sex.
• You use or used injection drugs and are likely to have shared unsterilized needles.
• You have an HIV-positive sexual partner.
• You have had sex with anyone who falls into one of the categories listed above or are uncertain about your sexual partner's risk behaviors.
• You've been diagnosed with or treated for hepatitis or tuberculosis (TB).
   

How often you are tested should depend on your risk, activities, and sexual contacts. For example, during a long-term, truly monogamous sexual relationship, you may want just one test. However, if you or your partner have had sexual contact with more than one person in recent months, your risk of infection is greater. If you or a person with whom you've had sexual contact (even unwanted sexual contact) engaged in some risky behavior, you have even more reason to be tested.

Screening Tests
Different types of tests are available for HIV screening:

• Combination HIV antibody and HIV antigen test—this is the recommended screening test for HIV. It is available only as a blood test. It detects the HIV antigen called p24 plus antibodies to HIV-1 and HIV-2. (HIV-1 is the most common type found in the United States, while HIV-2 has a higher prevalence in parts of Africa.) By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. These tests can detect HIV infections in most people by 2-6 weeks after exposure.
• HIV antibody testing—all HIV antibody tests used in the U.S. detect HIV-1, and some tests have been developed that can also detect HIV-2. These tests are available as blood tests or tests of oral fluid. HIV antibody tests can detect infections in most people 3-12 weeks after exposure.
   

Various options are available for getting tested:

• A blood or oral sample can be collected in a healthcare provider's office or a local clinic and sent to a laboratory for testing. In these same settings, a rapid test may available in which results are generated in about 20 minutes.
• A home collection kit approved by the U.S. Food and Drug Administration (FDA) is available for HIV antibody testing. This allows a person to take a sample at home and then mail it to a testing center. Results are available over the phone, along with appropriate counseling.
• The FDA has approved an HIV test for home use. The testing kit is the same as that used in many healthcare providers' offices and clinics in which an oral sample is collected for testing and results are available in about 20 minutes. Though the home test is convenient, it has limitations. It is less sensitive than a blood test so the home test may miss some cases of HIV that a blood test would detect and it is not as accurate when it is performed at home by a lay person compared to when it is performed by a trained healthcare professional. Care must be taken to avoid errors when performing the test. (For more, see the article on Home Testing, Avoiding Errors.)
   

Screening tests have limitations, so it is important to remember that:

• A negative screening test means only that there is no evidence of disease at the time of the test. If you have increased risk of HIV infection but negative screening results, it is very important to get screening tests on a regular basis.
• HIV tests will not detect the virus immediately after infection. Still, talk to your healthcare provider immediately if you think you’ve been infected. If exposure to the virus is recent, then antibody levels may be too low to detect. If an initial test is negative, it may be necessary to repeat testing at a later time with another antibody test or combination HIV antibody/antigen test. In the case of a negative result, the CDC recommends retesting three months after likely exposure.
• A positive screening test is not a diagnosis. A positive result must be followed by a second antibody test that differentiates between HIV-1 and HIV-2 to establish a diagnosis.
   

For more details on HIV screening, see the article on HIV Antibody and p24 Antigen.

Screening Recommendations

• The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 to 64 years old have an HIV screening test at least once. The CDC recommends getting tested each year if you've engaged in an activity that can put you at increased risk of infection and spreading the disease. Additionally, men who have sexual contact with other men should be tested be tested every three to six months.
• The United States Preventive Services Task Force (USPSTF) recommends that all teens and adults ages 15 to 65 be screened for HIV infection. It also recommends that younger adolescents and older adults at increased risk undergo screening for HIV. As for how often, the Task Force says a reasonable approach is one-time testing for all people ages 15 to 65 and at least annual screenings for those at very high risk of HIV, such as men who have sex with men, injection drug users, and those who live or receive medical care in areas where the rate of HIV infection is high. Individuals at increased but not very high risk may be screened less frequently than every year. The USPSTF recommends every three to five years as a guideline. The Task Force points out that risk is "on a continuum" and health professionals should use their own discretion in deciding how frequently to test people for HIV.
• The American College of Physicians agrees with the CDC that everyone aged 13 to 64 be offered an HIV screening test in healthcare settings. It also recommends that healthcare practitioners should determine the frequency of repeat screening on an individual basis.
• The American Academy of Pediatrics (AAP) recommends targeted HIV screening for all sexually active youth. In addition, the academy advises routine testing starting at age 16 for all teens who live in areas where prevalence is high; that is, where more than 1 in 1,000 individuals are infected.
• For recommendations specific for pregnant women, see the article on Pregnancy.
   

Aside from these recommendations, certain individuals should get tested and learn their status. These include:

• People diagnosed with hepatitis, TB, or an STD
• People who received a blood transfusion prior to 1985 or had a sexual partner who received a transfusion and later tested positive for HIV
• A healthcare worker with direct exposure to blood on the job
• Any individual who thinks he or she may have been exposed
   

Talk to your healthcare provider
Don't be surprised if a healthcare practitioner, in any care setting, offers you an HIV screening test, in keeping with CDC recommendations. If your healthcare provider does not bring up sexual health topics, you can simply ask for a test or a risk assessment. You can also use confidential services to obtain testing or counseling.

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Resources & Links

Tests: HIV Antibody and Antigen

Conditions: HIV Infection and AIDS

For confidential information, you can call the STDs and HIV/AIDS hotline of the CDC: 800-CDC-INFO (232-4636).
To find a testing site near you, visit National HIV and STD Testing Resources

Sources Used in Current Review (Last reviewed 1/11/17)

Qaseem, A. et al. (2009 January 20). Screening for HIV in health care settings: A guidance statement from the American College of Physicians and HIV Medicine Association. Annals of Internal Medicine. Available online at http://annals.org/aim/article/744218/screening-hiv-health-care-settings-guidance-statement-from-american-college. Accessed 11/6/2016.

(2011 October 31). The pediatrician's role in preventing HIV infection. American Academy of Pediatrics. Available online at https://healthychildren.org/English/news/Pages/The-Pediatricians-Role-in-Preventing-HIV-Infection.aspx. Accessed 11/6/2016.

(2013 April). Human Immunodeficiency Virus (HIV) infection: Screening. U.S. Preventive Services Task Force. Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/human-immunodeficiency-virus-hiv-infection-screening. Accessed 11/6/2016.

(2015 May 27). Press release: Starting antiretroviral treatment early improves outcomes for HIV-infected individuals. National Institutes of Health. Available online at https://www.nih.gov/news-events/news-releases/starting-antiretroviral-treatment-early-improves-outcomes-hiv-infected-individuals. Accessed 11/6/2016.

(Updated 2016 January 22). Working in healthcare and HIV. AVERT. Available online at http://www.avert.org/hiv-transmission-prevention/working-healthcare. Accessed 11/6/2016.

(2016 May 23). Recommendations for HIV prevention with adults and adolescents with HIV. Centers for Disease Control and Prevention. Available online at http://www.cdc.gov/hiv/guidelines/personswithhiv.html. Accessed 11/6/2016.

(2016 October 27). HIV and AIDS: Testing. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hiv/basics/testing.html. Accessed 11/6/2016.

(2016 June 20). HIV testing. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hiv/testing. Accessed 11/6/2016.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis bacteria. TB primarily targets the lungs but may affect any area of the body. It can be spread through the air from person to person through droplets of respiratory secretions such as sputum or aerosols released by coughing, sneezing, laughing, or breathing.

Most people who become infected with M. tuberculosis manage to confine the mycobacteria to a few cells in their lungs, where they stay alive but in an inactive form. This latent TB infection does not make the person sick or infectious and, in most cases, it does not progress to active tuberculosis. However, some people - especially those with compromised immune systems - may progress directly from initial TB infection to active tuberculosis. People who have HIV are much more likely to become sick if they contract TB. Another increasing concern is drug-resistant forms of TB that are resistant to the antibiotics typically prescribed to treat the disease.

According to the U.S. Centers for Disease Control and Prevention (CDC), TB in children is a public health concern because it is a marker for recent transmission of the bacteria, and infants and young children are more likely than older children and adults to develop life-threatening forms of the disease. Among children, the most cases of TB are seen in those under 5 years of age and in adolescents older than 10 years of age.

TB is one of the world's deadliest diseases, although it is relatively uncommon in the U.S. Still, it is a large health issue among at-risk groups. Current guidelines call for targeted screening among such groups.

Recommendations

The American Academy of Pediatrics (AAP) recommends that children and teens who are at risk of contracting TB have a tuberculin skin test, such as if:

• They have been exposed to someone with active or suspected TB (e.g., a family member or other contact)
• They are immigrants from a country where TB is endemic or have traveled to those countries for more than one week

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Links
CDC: Tuberculosis (TB) in Children in the United States
HealthyChildren.org (AAP): Tuberculosis in Children

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Sources Used in Current Review

U.S. Centers for Disease Control and Prevention. Tuberculosis (TB) in Children in the United States. Available online at http://www.cdc.gov/tb/topic/populations/tbinchildren/default.htm. Accessed October 2016.

HealthyChildren.org. Tuberculosis in Children. Available online at http://www.healthychildren.org/English/health-issues/conditions/chest-lungs/Pages/Tuberculosis.aspx?nfstatus=401&nftoken=00000000-0000-0000-0000-000000000000&nfstatusdescription=ERROR%3a+No+local+token. Accessed October 2016.

According to the Centers for Disease Control and Prevention (CDC), approximately 850,000 to 2.2 million people in this country have chronic infection with hepatitis B virus (HBV). Many of these people are unaware that they are infected.

HBV is one of five "hepatitis viruses" identified so far that are known to mainly infect the liver. It is spread through contact with blood or other body fluids from an infected person, such as during sex or by sharing needles, razors or toothbrushes, and can also be passed from an infected mother to her baby during or after birth.

HBV infection can be acute or chronic, with the course of infection varying from a mild form that lasts only a few weeks to a more serious form lasting years that can lead to complications such as cirrhosis or liver cancer. According to the Centers for Disease Control and Prevention (CDC), approximately 1,800 people die every year in the U.S. from HBV-related liver disease.

The vast majority of those with chronic infections will have no symptoms. A test for hepatitis B surface antigen (HBsAg) may be used for screening asymptomatic people who fall into one of the high-risk categories for chronic HBV. Effective vaccines against HBV are available; however, those who have not been vaccinated or who are at high risk and were vaccinated before being screened for HBV infection may want to consider getting tested.

Recommendations
Since the prevalence of HBV infection is low in the general U.S. population and most of those infected do not develop complications, HBV screening is not recommended for those who are not at increased risk.

For people with increased risk of infection, several health organizations including the CDC, the American Association for the Study of Liver Diseases (AASLD), the U.S. Preventive Services Task Force and the American Academy of Pediatrics recommend screening for HBV. Examples of people at risk include:

• Healthcare and public safety workers with possible exposure to infected blood or other body fluids
• People born in areas of the world that have a greater than 2% prevalence of HBV (for example, much of Asia and Africa), regardless of whether they have been vaccinated
• People born in the U.S. but who were not vaccinated early in life and whose parents are from an area with greater than 8% prevalence of HBV
• Men who have sex with men
• Injection drug users
• People who have elevated liver enzymes (ALT and AST) with no known cause
• People with certain medical conditions that require that their immune system be suppressed, such as organ transplant recipients
• Dialysis patients
• People who are in close contact with someone infected with HBV or who have a sexual partner with HBV (i.e. have tested positive for HBsAg)
• Those infected with HIV
• People who were vaccinated for HBV after they had already begun high-risk behavior (e.g., men who have sex with men and injection drug users)
   

In addition, the AASLD recommends HBV screening for:

• People with multiple sex partners
• Those who have a history of sexually transmitted diseases (STDs)
• Prison inmates
• People with hepatitis C infection
   

Recommendations for HBV screening during pregnancy are addressed separately. For more information, read the Pregnancy article.

Why get tested?
People with chronic HBV can unknowingly spread the infection to others and remain at risk for serious complications of the infection.

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Related Content
Tests: Hepatitis B Testing
Conditions: Hepatitis

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Sources Used in Current Review (last reviewed 10/11/17)

LeFevre, M. (2014 July 1). Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine V 161 (1). Available online at https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/hepatitis-b-virus-infection-screening-2014. Accessed on 8/06/17.

(2016 May 23, Updated). Hepatitis B FAQs for the Public. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/hbv/bfaq.htm. Accessed on 8/06/17.

(2015 March). Guidelines for the Prevention, Care and Treatment of Persons with Chronic Hepatitis B Infection. World Health Organization. Available online at http://apps.who.int/iris/bitstream/10665/154590/1/9789241549059_eng.pdf Accessed on 8/06/17.

(2017 May 11 Updated). Viral Hepatitis. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/statistics/index.htm Accessed on 8/06/17.

(2016 August 4, Updated). Hepatitis B FAQs for Health Professionals. Centers for Disease Control and Prevention. Available online at https://www.cdc.gov/hepatitis/hbv/hbvfaq.htm. Accessed on 8/06/17.

Hillyard, D. and Slev, P. (2017 July Updated). Hepatitis B Virus – HBV. ARUP Consult. Available online at https://arupconsult.com/content/hepatitis-b-virus/?tab=tab_item-2. Accessed on 8/06/17.

Workowski, K. and Bolan, G. (2015). Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR June 5, 2015 / 64(RR3);1-137. Available online at https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6403a1.htm. Accessed on 8/06/17.