Most STIs are treatable. Many have no symptoms at all. That's why regular testing matters — even if you feel fine. If you're MSM (a man who has sex with men) — every 3 months. Testing is free and anonymous.
How to get tested for free
SHL.UK — London, test delivered to your door in 2 days.
SH.UK — all of England.
Walk-in clinics — find your nearest on the NHS website.
A standard test covers: chlamydia, gonorrhoea, HIV, syphilis. For MSM — swabs from throat, genitals and rectum.
You need to ask separately for: hepatitis B and C, mycoplasma.
most common STI
Chlamydia
The most common STI. Often has NO symptoms at all. If present: discharge, burning when peeing, pain in the testicles. Treated with antibiotics — one course and done.
bacterial
Gonorrhoea
Yellow/green discharge, burning. Often no symptoms — especially in the throat and rectum. Treated with antibiotics (injection + tablets).
rising among MSM
Syphilis
Painless sores, then a rash on palms and soles. If untreated — damages the brain and heart. Treated with antibiotics. Rising among MSM — get tested regularly.
treatment is free
HIV
First symptoms feel like flu (2-6 weeks after infection). Then years without symptoms. Treatment is free for everyone in the UK — even without immigration status. U=U — undetectable means untransmittable. PrEP is free. More →
vaccine available
Hepatitis B
A liver virus. Often no symptoms. Spread through sex and blood. THERE IS A VACCINE — free for MSM. Chronic hepatitis B can't be fully cured but is managed with medication.
curable
Hepatitis C
Spread through blood (needles, razors, sex involving blood). Often no symptoms for YEARS. Good news: it's CURABLE — tablets for 8-12 weeks and the virus is gone.
vaccine available
HPV (Human Papillomavirus)
Extremely common. Genital warts — or NOTHING at all. Some types cause cancer (anal, cervical, throat). THERE IS A VACCINE — free for MSM up to age 45. Ask at a sexual health clinic.
not curable, but manageable
Herpes (HSV)
Painful blisters on genitals or around the mouth. Not fully curable, but outbreaks become less frequent over time. Antiviral medication helps. Spread through skin-to-skin contact.
vaccine free for MSM
Mpox
Rash with blisters, fever, muscle pain. Vaccine is free for MSM. If you suspect it — call a sexual health clinic first, don't walk in without calling.
not in standard tests
Mycoplasma genitalium
Similar to chlamydia but NOT included in standard tests. Ask for it separately if you have symptoms — discharge, burning. Treated with antibiotics.
condoms don't protect
Pubic lice and scabies
Itching is the main symptom. Treated with cream or special shampoo. Condoms don't protect — spread through close skin-to-skin contact.
When to see a doctor urgently
- Unusual discharge
- Pain when peeing
- Sores or rash on your genitals
- Pain in the lower abdomen
→ Go to a sexual health clinic, not your GP — it's faster and more confidential.
Important: This page is for information, not self-diagnosis. Many STIs have no symptoms. Test regularly at a sexual health clinic. If you have symptoms — see a doctor. Source: NHS.