About STIs
Sexually transmitted infections (STIs) are infections that can be passed from one person to another during close sexual contact; whether oral, vaginal or anal sex. They can also be spread by sharing sex toys or aids.
Anyone who is sexually active can catch an STI, regardless of age, gender or sexuality. Having sex without using a condom, or not using a condom correctly, puts you at a higher risk.
STIs can cause discomfort, embarrassment and irritation. They can also have longer-term effects on your health, including pain and infertility. Some of the STIs that can cause long-term damage to our bodies can sometimes have no symptoms at all.
Common infections which cause irritation and discharge, such as thrush and bacterial vaginosis, are not sexually shared.
Information about common STIs
Chlamydia
Chlamydia is the most common STI in the UK and is easily passed on during sex. Most people don't experience any symptoms, so they are unaware they're infected. Find out more...
Epididymo-orchitis
Epididimo-orchitis is a common condition which affects only men and is characterised by pain and swelling inside the scrotum (testicles). Find out more...
Genital Herpes
Genital herpes is a common infection caused by the herpes simplex virus (HSV), which is the same virus that causes cold sores. Find out more...
Genital warts
Genital warts are small fleshy growths, bumps or skin changes that appear on or around your genital or anal area. They're caused by the human papilloma virus (HPV) and are the second most common STI in the UK. Find out more...
Gonorrhoea
Gonorrhoea is a bacterial STI easily passed on during sex. About 50% of women and 10% of men don't experience any symptoms and are unaware they're infected. Find out more...
Hepatitis B
Hepatitis B is very infectious (it’s 100 times more infectious than HIV) and is very easily transmitted through unprotected sex or by sharing needles to inject drugs. Most people who contract hepatitis B don’t have symptoms. If symptoms do occur, they can appear one to six months after coming into contact with the virus. Find out more...
HIV
HIV is most commonly passed on through unprotected sex. It can also be transmitted by coming into contact with infected blood – for example, sharing needles to inject drugs or steroids. Find out more...
Molluscum Contagiosum
Molluscum Contagiosum is a common and generally harmless viral infection of the skin. It’s caught by direct contact with the skin and is most common in children and young adults, although it can occur at any age. Find out more...
Non-gonococcal Urethritis/ Non Specific Urethritis (NGU/NSU)
Urethritis is inflammation (pain, redness or soreness) of the urethra (the tube that carries urine out of the body). You can only get this infection if you have a penis. It is very common and is usually easy to treat. Find out more...
Pelvic Inflammatory Disease (PID)
PID is the name given to inflammation of a woman’s organs (the womb, fallopian tubes, ovaries or surrounding tissues). It is usually caused by a bacterial infection that spreads from the cervix (neck of the womb) up into these organs. Find out more...
Pubic lice
Pubic lice, sometimes known as crabs, are easily passed to others through close genital contact. They're usually found in pubic hair but can live in underarm hair, body hair, beards and, occasionally, eyebrows or eyelashes. Find out more...
Scabies
Scabies is caused by tiny mites that burrow into the skin. It can be passed on through close body or sexual contact, or from infected clothing, bedding or towels. Find out more...
Syphilis
Syphilis is a bacterial infection that causes a painless, but highly infectious, sore on your genitals in the early stages. The sore can last up to six weeks before disappearing. Find out more...
Trichomonas
Trichomonas is an STI caused by a tiny parasite called trichomonas vaginalis (TV). It can be easily passed on through sex and most people don't know they're infected. Find out more...