HIV testing options: clinic, home self-test and postal tests explained

The NHS lists places to get an HIV test: sexual health clinics, a GP, clinics run by charities such as Terrence Higgins Trust, some contraception clinics, some young people's services, A&E if you have been exposed in the last 72 hours, and private clinics where you pay. Terrence Higgins Trust says testing at a sexual health clinic, an HIV testing centre or a GP is free, and tests at a private clinic are paid for.

If you do not want to or cannot test in person, you can order a self-test, which you take yourself and read within minutes, or a postal test, where you take a sample and send it to a laboratory that contacts you with the result. The NHS says to choose a kit clearly marked for self-testing, with a CE mark and manufacturer details, which is not damaged and whose seal is not broken.

Terrence Higgins Trust explains that an HIV test is a blood test (finger-prick or oral swab in rapid and self-tests). It does not detect the whole virus itself; it looks for a protein found in an HIV cell, or an antibody made by the body to fight HIV. The NHS says HIV tests use saliva from the mouth or blood from a finger, and that in a clinic the sample usually goes to a laboratory with results within a few days.

Results time depends on the type of test.

The window period is the time between exposure and when a test can accurately detect infection. Terrence Higgins Trust says national testing guidelines set a 90-day window for HIV self-tests, while blood tests sent to a lab and those at sexual health clinics have a window of 45 days. In practice, a self-test tells you your status 90 days ago and a clinic blood test your status 45 days ago.

If your risk was recent, the provider will probably advise testing immediately and again a few weeks later. The NHS says a negative result means no signs of infection were found, and you may be advised to test again a few weeks later if you were exposed in the last few weeks. Terrence Higgins Trust says if your risk was in the last three months, tell the person testing you, since it may affect the type of test, and a self-test is not guaranteed to pick up an infection acquired in that time. If you think you were exposed in the last 72 hours, post-exposure prophylaxis (PEP) can help stop infection and is available from sexual health clinics and A&E.

Terrence Higgins Trust says HIV tests in the UK are very reliable. A false positive, a positive that turns out negative on retesting, is rare, in under 1 in 1,000 cases. False negatives most often occur when someone tests within the window period, before markers reach detectable levels. That is why timing matters more than the brand of test.

Pregnant women are offered an HIV blood test as part of routine antenatal screening for hepatitis B, HIV and syphilis, according to the NHS.

The NHS says a positive result means you could have HIV, and you will need a blood test at a clinic; if that second test is also positive you will be referred to an HIV clinic for more tests and to discuss treatment. With treatment, the NHS says most people with HIV can live a long and healthy life and people on effective treatment with an undetectable viral load cannot pass the virus on. Support from Terrence Higgins Trust and the National AIDS Trust is available.

If you feel anxious while waiting for a result, a sexual health clinic can talk it through; for urgent mental health distress use NHS 111, or 999 in an emergency.