The only way to know if you have HIV or the more advanced stage of the infection, AIDS, is to get tested. The CDC recommends that everyone between ages 13 and 64 have an HIV test at least once. You should also have one if you’ve had unprotected sex, injected drugs, or you’ve been diagnosed with tuberculosis, hepatitis, or an STD.
To get tested, you’ll need to give a sample of your blood, saliva, or urine. There are a few types of tests health care providers use to diagnose HIV:
CD4 cells are a type of white blood cell that fights infection. Another name for them is T-helper cells. CD4 cells are made in the spleen, lymph nodes, and thymus gland, which are part of the lymph or infection-fighting system. CD4 cells move throughout your body, helping to identify and destroy germs such as bacteria and viruses.
The CD4 count measures the number of CD4 cells in a sample of your blood drawn by a needle from a vein in your arm. Along with other tests, the CD4 count helps tell how...
An antibody screening test (also called an immunoassay) looks for antibodies -- proteins your body makes when it fights invaders like the HIV virus. Most people form antibodies the test can detect within 3 months after they’re infected, but it can take up to 6 months for a few.
Another test looks for antibodies and a substance made by the virus, called an antigen. It can find HIV in as little as 2 weeks after you’ve been exposed.
The RNA test, which looks for the virus itself instead of antibodies, can diagnose HIV about 10 days after exposure. It’s expensive, though, and doctors don’t usually recommend it as a first screening.
Some tests take a few days for results, but rapid HIV tests, a type of immunoassay, give results in 30 minutes or less.
Two at-home HIV tests are approved by the FDA. For the Home Access HIV-1 Test System, you prick your finger to collect a blood sample and mail it to a lab for testing. For the OraQuick In-Home HIV Test, you swab the inside of your mouth, use the kit to test it, and get results right away. It may be less accurate than the Home Access system, though.
No matter which test you use, results that say you have the virus require follow-up testing to confirm an HIV diagnosis.
What Happens After an HIV Test?
It can be stressful to get tested, but it’s important to take that step. Early treatment can prevent HIV from becoming AIDS, the most advanced stage of the disease.