Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK so, if you're thinking of having sex, it's important that you know what Chlamydia is, how you get it and what to do if you've got it. Remember whether it causes symptoms or not, chlamydia can damage your insides.

Whether it causes symptoms or not, chlamydia can damage our insides

What is it?

Chlamydia is a sexually transmitted infection that is caused by tiny bacterium.

You pick it up through unprotected vaginal, oral or anal sex. It affects both sexes.

According to, in 2016, there were 417,584 new STI diagnoses made at sexual health services* (SHSs) in England. Of these, the most commonly diagnosed STIs were chlamydia (202,546; 49% of all new STI diagnoses)

How do I know if I've got it?

Symptoms include pain while peeing, discharge from the penis or pain in the testicles for boys. Girls may experience tummy ache, bleeding after sex or between periods, pain on peeing or changes in their usual vaginal discharge.

Chlamydia can also infect the back passage (the rectum), throat and the eyes, urethra and cervix.

According to Sexwise, "more than 2 in 3 women and 1 in 2 men with chlamydia won’t have any obvious signs or symptoms, or will have symptoms so mild they’re not noticed.”

The bugs lurk inside us, but we are none the wiser.

So why does it matter if I get it?

Whether it causes symptoms or not, if left untreated, chlamydia can damage our insides which can then lead to pelvic inflammatory disease, inflammation of the testicles, and infertility (the inability to have babies) amongst other complications. The simple way to protect yourself from infection is to always use a condom. Every time. It's a no brainer.

How can I be sure I haven't got it now?

If you're concerned, take the test – a urine or swab test in most cases and sometimes you may need a physical examination - visit your GP, Young People's or Sexual Health clinic, also called a GUM clinic and some chemists.

You can find out more about who is advised to have the test here. The NHS also offers testing under the National Chlamydia screening programme (NCSP) to help diagnose infection in people who do not show any symptoms.

You can buy testing kits but it is best to ask your doctor or chemist about the particular kit you are using because their accuracy can vary.

Then what?

If your test comes back positive, you'll take a short course of antibiotics. That's it - treatment is very straightforward. It's likely you'll be advised not to have sex for seven days following treatment.

For more information about STIs and chlamydia visit the NHS website.

Click on the link to find a sexual health clinic in your area.

BBC Advice factfiles are here to help young people with a broad range of issues. They're based on advice from medical professionals, government bodies, charities and other relevant groups. Follow the links for more advice from these organisations.

This factfile was updated on the 15 May 2018


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