Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK. It’s passed on through unprotected sex and is particularly common in sexually active teenagers and young adults.

Chlamydia is a bacterial infection. Chlamydia is passed on by unprotected sex (oral, vaginal or anal) with someone who has the infection. It can also be passed on by genital contact and sharing sex toys. If you or someone you have has sex with tests positive for chlamydia, it’s important that you’re screened for other STIs, too. Contact your local NHS clinic to get a confidential screening.

Many people with chlamydia don’t get symptoms. 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 can usually be treated easily with antibiotics. Doxycycline is an antibiotic used for the treatment of chlamydia in people who have either tested positive or had sexual contact with someone who has it.

Anyone who’s sexually active can catch chlamydia, but you can prevent catching it by having protected sex: Use a condom every time you have vaginal or anal sex. Cover the penis with a condom during oral sex. Use a dam (a piece of thin, soft plastic or latex) to cover the vulva during oral sex or genital contact. Don't share sex toys.