Types of HIV tests

Antibody tests are often used to screen for HIV. Antibodies are things that the body makes to try to fight infections, such as HIV. Antibody tests look for antibodies to HIV, rather than the HIV itself. Antibodies to HIV often can be found between two weeks and three months after infection. Depending on the test and the place where you are tested, results come back within a few minutes to a few weeks. Ask your doctor or testing center how long you must wait.

These are some kinds of antibody tests:

Enzyme immunoassay (EIA) tests. These tests are the most common and give results in a day to one to two weeks.
Rapid tests. These are antibody tests that give you results quickly, usually in about 20 minutes. Rapid tests use blood from a vein or a finger stick or fluid from your mouth to look for antibodies to HIV. If you are HIV-negative, these are just as accurate as the EIA test. If you test HIV-positive with this test, you will need a follow-up blood test to confirm the results.
Home Access Test. With this antibody test, you take your blood sample at home and mail it to a lab for testing. Results are provided over the phone by a counselor. You do not have to give your name. You will receive an ID number to use when you call for the results. There is only one home test approved by the U.S. Food and Drug Administration (FDA): Home Access HIV-1 Test System . It takes about seven days to get test results. Home Access also makes an express test with results available the day the lab receives your shipment. It takes three to seven days to get test results. You can buy this FDA-approved test online or at the drugstore. Beware: Online you can buy several HIV home test kits that are not approved by the FDA. Many of these tests give wrong results.
If you test positive with an antibody screening test, you will need a second type of test to confirm that you are infected. You must wait a few days to a few weeks for the results.