Chlamydia is 1 of the most common sexually transmitted infections (STIs) in the UK. It’s passed on through unprotected sex (sex without a condom) and is particularly common in sexually active teenagers and young adults.

If you live in England, are under 25 and are sexually active, it’s recommended that you get tested for chlamydia every year or when you change sexual partner.

Most people with chlamydia do not notice any symptoms and do not know they have it.

If you do develop symptoms, you may experience:

• pain when peeing
• unusual discharge from the vagina, penis or bottom
• in women, pain in the tummy, bleeding after sex and bleeding between periods
• in men, pain and swelling in the testicles

Chlamydia is a bacterial infection. The bacteria are usually spread through sex or contact with infected genital fluids (semen or vaginal fluid)