HIV Overview

HIV testing determines if a person is infected with HIV. The human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). AIDS is the most advanced stage of HIV infection.

HIV testing can detect HIV infection, but it cannot tell how long a person has had HIV or if the person has AIDS.

Knowing your HIV status can help keep you—and others—safe.

If you are HIV negative:

A negative HIV test result shows that you do not have HIV. Continue taking steps to avoid getting HIV, such as using condoms during sex and, if you are at high risk of getting HIV, taking medicines to prevent HIV (called pre-exposure prophylaxis or PrEP). For more information, read the HIVinfo fact sheet on The Basics of HIV Prevention.

If you are HIV positive:

A positive HIV test result shows that you have HIV, but you can still take steps to protect your health. Begin by talking to your health care provider about antiretroviral therapy (ART). People on ART take a combination of HIV medicines every day to treat HIV infection. ART is recommended for everyone who has HIV, and people with HIV should start ART as soon as possible. ART cannot cure HIV, but HIV medicines help people with HIV live longer, healthier lives.

A main goal of ART is to reduce a person’s viral load to an undetectable level. An undetectable viral load means that the level of HIV in the blood is too low to be detected by a viral load test. People with HIV who maintain an undetectable viral load have effectively no risk of transmitting HIV to their HIV-negative partner through sex.

The Centers for Disease Control and Prevention (CDC) recommends that everyone 13 to 64 years of age get tested for HIV at least once as part of routine health care. As a general rule, people at higher risk for HIV should get tested each year. Sexually active gay and bisexual men may benefit from getting tested more often, such as every 3 to 6 months. If you are over 64 years of age and at risk, your health care provider may recommend HIV testing.

Factors that increase the risk of HIV include:

• Having vaginal or anal sex with someone who is HIV positive or whose HIV status you do not know
• Injecting drugs and sharing needles, syringes, or other drug equipment with others
• Exchanging sex for money or drugs
• Having a sexually transmitted disease (STD), such as syphilis
• Having sex with anyone who has any of the HIV risk factors listed above

Talk to your health care provider about your risk for HIV and how often you should get tested for HIV.

CDC recommends that all pregnant women get tested for HIV so that they can begin taking HIV medicines if they are HIV positive. Women with HIV take HIV medicines during pregnancy and childbirth to reduce the risk of perinatal transmission of HIV and to protect their own health. For more information, read the HIVinfo fact sheet on Preventing Perinatal Transmission of HIV.

There are three types of tests used to diagnose HIV infection: antibody tests, antigen/antibody tests, and nucleic acid tests (NATs). Your health care provider can determine the appropriate HIV test for you. How soon each test can detect HIV infection differs, because each test has a different window period. The window period is the time between when a person may have been exposed to HIV and when a test can accurately detect HIV infection.

• Antibody tests check for HIV antibodies in blood or oral fluid. HIV antibodies are disease-fighting proteins that the body produces in response to HIV infection. Most rapid tests and home use tests are antibody tests.
• Antigen/antibody tests can detect both HIV antibodies and HIV antigens (a part of the virus) in the blood.
• NATs look for HIV in the blood.

A person’s initial HIV test will usually be either an antibody test or an antigen/antibody test. NATs are very expensive and not routinely used for HIV screening unless the person had a high-risk exposure or a possible exposure with early symptoms of HIV infection.

When an HIV test is positive, a follow-up test will be conducted. Sometimes people will need to visit a health care provider to take a follow-up test. Other times, the follow-up test may be performed in a lab using the same blood sample that was provided for the first test. A positive follow-up test confirms that a person has HIV.

Talk to your health care provider about your HIV risk factors and the best type of HIV test for you.

HIV testing can be confidential or anonymous. 

Confidential testing means that your HIV test results will include your name and other identifying information, and the results will be included in your medical record. HIV-positive test results will be reported to local or state health departments to be counted in statistical reports. Health departments remove all personal information (including names and addresses) from HIV test results before sharing the information with CDC. CDC uses this information for reporting purposes and does not share this information with any other organizations, including insurance companies.

Anonymous testing means you do not have to give your name when you take an HIV test. When you take the test, you receive a number. To get your HIV test results, you give the number instead of your name.

Your health care provider can give you an HIV test. HIV testing is also available at many hospitals, medical clinics, substance use programs, and community health centers. Use CDC's GetTested treatment locator to find an HIV testing location near you. Getting tested through a professional health care provider is recommended; however, there are HIV self-testing kits available. Rapid self-test and mail-in self-test are the two types of HIV self-tests, but state laws regarding self-testing may limit their availability in a location.

A rapid self-test is an oral fluid test done entirely at home or in private. There is currently one U.S. Food and Drug Administration (FDA)-approved rapid self-test called OraQuick In-Home HIV test. A mail-in self-test requires a person to provide a blood sample from a fingerstick, which is then sent to a lab for testing.

From CDC:

• Getting Tested
• HIV Basics: Testing
• HIV Testing
• Self-Testing
• Self-Testing: A Convenient and Private Option

From FDA:

• OraQuick In-Home HIV Test

Also see the HIV Source collection of HIV links and resources.