How common is chlamydia?

After HPV, chlamydia is the most common STI in the UK and is especially high amongst young people. Stigma can make it harder for people to test so we thought we'd show you exactly how common chlamydia is...

Public Health England reported 435000 diagnoses of STIs in England in 2015. Out of those 435000, 200288 were chlamydia diagnoses 

For context that's:

You’d need  


                                                                 to get them there


The number of people who tested positive for chlamydia is roughly the same as the entire population of Gateshead.

image courtesy of  plantronicsgermany  (CC; Flickr)

image courtesy of plantronicsgermany (CC; Flickr)


In 2015, 1.5 million chlamydia tests were carried out in 18-24 year olds.

439,370 of these were urine tests, which adds up to.... 

                                                                                             ...pints of pee

1,069,581 swabs were used which, end to end, would cover 106 miles - further than the distance from London to Calais 

and that's only amongst 18-24 year olds!

So as you can see chlamydia is very common, and those are only the known cases. 

Chlamydia is often symptomless and if left untreated can lead to reduced fertility and pregnancy complications, so the sooner it is diagnosed the better.  If you think you could have come into contact with chlamydia you need to get tested, so that you can receive treatment if necessary. It takes up to two weeks after transmission for chlamydia to show up on an STI test so better to wait until 2 weeks have passed -check out our site for more information. You should use condoms until your results come through to avoid transmission. If you do get a positive diagnosis the best thing you can do is help stop the spread by notifying any partners who may also have been exposed. As we've explained, it's hugely common and not a big deal, but your sexual health clinic can help you do it anonymously if you don't feel comfortable making the calls.

More information on chlamydia: Find a clinic: