The HIV test

HIV infection is normally detected using an HIV test. There are different types of test - one test looks for the antibodies the immune system produces to fight HIV infection. Another test looks for the HIV itself (called an antigen test, or a p24 test).

Most clinics use a test which includes both of these types - an antibody test and an antigen test. This means that HIV can be found sooner after infection than it would be by using an antibody test on its own.

Using this test, the overwhelming majority of people who have HIV can be diagnosed within one month of being infected. For a person whose last possible exposure to HIV was one month ago, a negative result should be very reassuring. Nonetheless for a very small number of people, it can take up to three months for the test to give an accurate result. 

If you have any concerns about taking an HIV test, or the results you have had, you can talk to someone (for example a health adviser) at your local clinic, so they can explain the process to you. 

The HIV test is not an ‘AIDS test'. There is no such thing.

Tests can also be used to look for parts of HIV's genetic material (a PCR – polymerase chain reaction – test), often called a viral load test. Viral load testing is covered in a lot more detail in the section Key tests to monitor HIV - CD4 and viral load .