Types of HIV Tests
Learn about the different types of HIV tests, their accuracy, and when to use each type.
Learn about the different types of HIV tests, their accuracy, and when to use each type.
A NAT looks for the actual virus in the blood. It can tell if a person has HIV or how much virus is present (viral load test). A NAT can usually detect HIV sooner than other types of tests. This test is very expensive and not routinely used for screening unless the person recently had a high-risk exposure or a possible exposure and has early symptoms of HIV infection.
This test looks for both HIV antibodies and antigens (p24 protein). It is recommended for testing done in labs and is now common in the United States. An antigen/antibody test performed by a laboratory on blood from a vein can usually detect HIV infection 18 to 45 days after an exposure.
Antibody tests check for HIV antibodies in blood, oral fluid, or urine. Most rapid tests and home tests are antibody tests. These tests can detect HIV 23 to 90 days after exposure. A rapid test can give results in 20 minutes or less. The OraQuick In-Home HIV Test is the only FDA-approved over-the-counter HIV test.
The window period is the time between HIV exposure and when a test can accurately detect HIV. During the window period, a person may have HIV but test negative. If you test negative but think you may have been recently exposed, you should test again after the window period has passed. The CDC recommends retesting 45 days and 90 days after a possible exposure.
Use these resources to find free, confidential HIV testing near you: