Sexual health testing: the basics

Many sexually transmitted infections cause no symptoms for long periods. Chlamydia, gonorrhoea and trichomoniasis are common examples. An asymptomatic infection can still be passed on and, if left untreated, can sometimes cause problems later, such as pelvic inflammatory disease.

That is why regular testing is more reliable than guessing. Testing is a normal part of looking after your health, in the same way as a dental check-up. A positive result is not a judgement about anyone: most STIs are curable, and the rest can be treated or managed well.

STI testing usually means a urine sample, swabs or a blood test, depending on which infections are being checked and what kind of sex someone has had. Many services offer self-sampling, where you take your own swab or sample at home or in a clinic and send it to a laboratory. A rapid HIV test can give a result within minutes.

A sexual health clinic offers confidential testing and treatment, and staff are used to every kind of question. It helps to be open about the type of contact you have had, because that guides which tests are needed.

Every test has a window period: the time between a possible exposure and the point when a test can reliably detect an infection. Testing too early can give a negative result even if an infection is present, so clinics sometimes suggest a repeat test later.

After a possible HIV exposure, timing works differently. PEP, a course of HIV medicine, has to be started as soon as possible, ideally within 72 hours, so it is worth contacting a sexual health clinic or emergency department straight away rather than waiting for a test.

Bacterial infections such as chlamydia, gonorrhoea and syphilis are treated with antibiotics. Viral infections such as genital herpes and HIV cannot currently be cured but can be managed. With antiretroviral therapy, people living with HIV can expect a near-normal lifespan, and someone with an undetectable viral load cannot pass HIV on through sex, a principle known as U=U.

Partner notification means letting recent partners know they may have been exposed, so they can be tested and treated too. Clinics can often do this anonymously on your behalf. In some places, expedited partner therapy lets a partner receive treatment without a separate appointment.

Safer sex combines several tools. Condoms and dental dams reduce the risk of many STIs. Vaccines protect against HPV and hepatitis B. PrEP, taken before possible exposure, greatly reduces the chance of getting HIV, and doxy-PEP is an antibiotic option some services offer to reduce certain bacterial STIs.

Language matters too. Saying "tested negative" rather than "clean" avoids implying that people with an infection are dirty, and makes honest conversations about status easier. This guide is general information: a sexual health clinic can advise on how often you should test.