Sexually transmitted infections (STIs)
A sexually transmitted infection, or STI, is an illness that can spread from one person to another through close contact, like during sex. Some STIs can make you feel sick, but others might not show any signs at all. Even if someone looks healthy, they can still have an STI. Doctors can help treat most STIs, and using protection, like condoms, can help stop them from spreading. It’s important to talk to a trusted adult or doctor if you have questions.
What to do if you think you have an STI
If you’re worried because you think you’ve got an STI, go for a check-up at a sexual health clinic as soon as you can. Sexual health clinics treat problems with the genitals and urine system. You can usually turn up without an appointment. No information about your visit to the clinic will be shared with the GP or anyone else outside the clinic unless you ask for it to be. You can ask to see a female or male doctor or nurse if you wish.
Do not have sex, including oral sex, without using a condom until you’ve had a check-up.
We offer a safe and reliable NHS self-testing at home service which you can order using our website. You must be a Welsh resident to access this testing service.
Common STIs
Chlamydia
Chlamydia infection, often simply known as chlamydia, is a sexually transmitted infection caused by the bacterium chlamydia trachomatis. Chlamydia is the most common sexually transmitted infection (STI) in the UK. If left untreated it can affect fertility in men and women.
Visit NHS 111 Wales for more information on chlamydia.
Gonorrhoea
Gonorrhoea is a sexually transmitted infection (STI) caused by a bacteria. It is the second most commonly reported bacterial STI in the UK after chlamydia.
Visit NHS 111 Wales for more information on gonorrhoea.
Trichomoniasis
Trichomoniasis is a sexually transmitted infection (STI) caused by a tiny parasite called Trichomonas vaginalis (TV). The symptoms of trichomoniasis are similar to those of many other sexually transmitted infections (STIs), so it can sometimes be difficult to diagnose.
Visit NHS 111 Wales for more information on trichomoniasis.
Genital warts
Genital warts are small fleshy growths, bumps or skin changes that appear on or around the genital or anal area. They are the result of infection with the most common viral STI and are caused by the human papilloma virus (HPV).
Visit NHS 111 Wales for more information on genital warts.
Herpes
Genital herpes is a long-term condition caused by the herpes simplex virus (HSV). The virus is highly contagious and spreads from one person to another through skin-to-skin contact, such as during vaginal, anal or oral sex.
Visit NHS 111 Wales for more information on herpes.
Syphilis
Syphilis is a curable bacterial infection that spreads easily through unprotected sexual activity. There are increasing numbers of cases of syphilis in Wales, so it is becoming more common than before. Syphilis can be a very serious infection if not treated, it will not go away without medication.
Having syphilis could make it easier for someone to contract or pass on HIV.
Visit NHS 111 Wales for more information on syphilis.
Mpox
Mpox (previously known as monkeypox) is a rare disease caused by infection with the mpox virus.
More information on Mpox can be found here.
HIV
Is a virus, Human Immunodeficiency Virus (HIV), that attacks the immune system.
More information on HIV can be found here.
Where can I go for advice on Hepatitis A, Hepatitis B and Hepatitis C ?
Detailed advice on Hepatitis A, Hepatitis B and Hepatitis C can be found within our topic pages.
Contact the Sexual Health Wales team
You can reach the team by emailing [email protected]. Please note that this mailbox is monitored Monday to Friday, 9am to 5pm.