The only way to know for sure whether you have HIV is to have an HIV test.
In the UK, HIV testing is free and confidential through NHS sexual health clinics, GPs and other health settings such as antenatal care. Many charities and community projects offer free HIV testing too.
Usually, when you go for an HIV test, you will have an opportunity to talk to someone first, so you can ask any questions you might have. The person doing the test will explain how the test works and how you will get the results.
Then, depending on the type of test, you have a small sample of blood taken from your arm, or a drop of blood taken from your finger. Some tests are performed using fluid from around your gums. You will either get the result straight away (from a ‘rapid test’) or the clinic will ask you to make another appointment to get the results.
If the test says you are HIV positive, this means you have HIV. If the test says you are HIV negative, this means you do not have HIV. With some tests, you will need to have a follow-up test if you have a positive result.
There are different types of test and they can look for the antibodies the immune system produces to fight HIV infection or look for the HIV itself (called an antigen test, or a p24 test).
Some test kits include 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 sexual health clinic, so they can explain the process to you.