Sexual infections and STI testing

What an STI is

A sexually transmitted infection, or STI, is an infection passed through sexual contact. Different infections spread in different ways, including oral, vaginal or anal sex and some close skin contact. Anyone can need advice, whatever their gender, identity or relationship. An infection is a health issue, not a reason for blame. Many infections can be cured; others can be managed with treatment.

Symptoms are not always present

Some infections cause no noticeable symptoms. Possible symptoms include unusual discharge, pain when peeing, sores, blisters, itching or unexpected bleeding. These can also have other causes, so do not diagnose an STI from symptoms alone. Contact a sexual health clinic if symptoms appear, a partner has an infection, or there is a concern after sex. Severe pain or serious illness needs urgent medical assessment, not just a postal test.

Find a suitable clinic

NHS sexual health clinics offer free STI testing and treatment. They may be called GUM clinics. A GP referral is usually unnecessary; check the clinic’s booking and walk-in arrangements. Ask about the NHS service before using a pharmacy, private clinic or commercial home test, where charges and available tests can differ. A learning disability should not stop someone accessing a sexual health service.

Ask for adjustments before the visit

Explain what helps with communication and examinations. This might include Easy Read information, extra time, an interpreter, a quiet space, wheelchair access, a communication aid or a trusted supporter. Staff should talk directly to the person. Ask whether a self-taken sample is suitable, if preferred. A supporter should help the person understand and express their wishes, rather than assume they can decide for them.

What tests might involve

The clinician asks about symptoms, medicines, when sexual contact happened and the kinds of contact involved. This helps them choose relevant tests, not judge the person. Testing may involve pee, blood or swabs; the body sites tested depend on the contact and symptoms. Some problems need an examination. Ask what each test checks and what it does not check. A routine test kit does not rule out every infection.

Timing: a negative early test may need repeating

The window period is the time after an infection begins before a particular test can reliably detect it. It differs by infection and test. Contact the clinic for an individual testing plan rather than waiting a fixed number of weeks for every STI. They may advise testing now and repeating some tests later. Symptoms, a partner’s diagnosis, pregnancy concerns or possible HIV exposure should be mentioned immediately.

Possible HIV exposure: do not wait for a routine test

PEP is emergency medicine that may prevent HIV after an exposure. Seek assessment immediately from a sexual health clinic or A&E. It should start as soon as possible, ideally within 24 hours and no later than 72 hours. A clinician decides whether it is appropriate. Do not wait for symptoms, a postal kit or another person’s test result. If more than 72 hours have passed, still seek testing and advice.

Consent, privacy and safe contact

Ask staff to explain tests before agreeing and tell them if you need to pause. You can request a particular examiner gender, a chaperone or chosen supporter. You can also ask to speak alone. Clinics normally keep information private, including from your GP, but may share information where necessary to protect someone from harm. Agree a safe way to receive results, especially if messages or post are monitored by another person.

Results, treatment and follow-up

Ask when results should arrive, who will explain them accessibly and whom to contact if nothing arrives. A positive result means discussing treatment and follow-up; it is not a judgement about the person. Follow the clinic’s advice about medicines, further tests and when sexual contact is safe again. Do not share medicines. If medicines, swallowing or remembering doses are difficult, ask the clinic and pharmacist to adapt the plan.

Helping partners get care safely

A clinic may need to help current or previous sexual partners obtain tests or treatment. Staff can often contact them without revealing who supplied their details. Tell the clinic if contact could expose someone to violence, control or other harm. Do not feel obliged to confront an unsafe partner. The clinic can discuss a safer approach and relevant safeguarding support.

Preventing infections and using home tests

Condoms reduce the risk of many STIs but do not remove every risk. Ask the clinic about suitable barriers and lubricant, and whether vaccinations or PrEP are appropriate. PrEP is medicine taken to prevent HIV before exposure; it is different from emergency PEP. Some areas offer NHS home sampling. Check eligibility, which infections are included, when to sample and how results and treatment will follow. Ask for a clinic appointment if a kit is unsuitable.

Young people and help after assault

People under 16 can seek confidential sexual health advice; staff must also consider safeguarding. If sexual contact happened without free agreement, a sexual assault referral centre can offer specialist care and advice. Routine STI testing is separate from collecting forensic evidence after an assault. Urgent pregnancy prevention or HIV assessment should not wait for a routine test appointment. See the separate assault guide for adult and child support routes.

Testing for sexual infections

Why testing matters

Contact a clinic

Support and different tests

Urgent help after possible HIV exposure

Privacy, results and treatment

What you can do next

More useful links