The only way to find out if you have HIV is to have an HIV test, as symptoms of HIV may not appear for many years. Anyone who thinks they could have HIV should get tested.
HIV testing is provided to anyone free of charge on the NHS. Many clinics can give you the result on the same day. Home testing and home sampling kits are also available.
Some people are at particularly high risk of becoming infected with HIV and may be advised to have regular tests.
Seek medical advice immediately if you think there's a chance you could have HIV. The earlier it's diagnosed, the earlier you can start treatment and avoid becoming seriously ill.
Some HIV tests may need to be repeated 1-3 months after exposure to HIV infection, but you should not wait this long to seek help.
A GP or a sexual health professional can talk to you about having a test and discuss whether you should take emergency HIV medicine.
Anti-HIV medicine called post-exposure prophylaxis (PEP) may stop you becoming infected if taken within 72 hours of being exposed to the virus.
There are various places you can go to for an HIV test, including:
Find HIV testing services near you
There are also home sampling and home testing kits you can use if you do not want to visit any of these places.
There are 4 main types of HIV test:
If the test finds no sign of infection, your result is "negative". If signs of infection are found, the result is "positive".
The blood test is the most accurate test and can normally give reliable results from 1 month after infection.
The other tests tend to be less accurate and may not give a reliable result for a longer period after exposure to the infection. This is known as the window period.
For all these tests, a blood test should be carried out to confirm the result if the first test is positive.
If this test is also positive, you'll be referred to a specialist HIV clinic for some more tests and a discussion about your treatment options.
If you're pregnant, you'll be offered a blood test to check if you have HIV as part of routine antenatal screening.
If untreated, HIV can be passed to your baby during pregnancy, birth or breastfeeding. Treatment in pregnancy greatly reduces the risk of passing HIV on to the baby.