4 minutes read4 minutes readSummary:
- Chlamydia diagnoses in England fell by around a tenth in 2025. It is still the most commonly diagnosed STI, making up nearly half of all new STI diagnoses.
- Fewer diagnoses doesn’t mean Chlamydia has gone away. Fewer young people were tested, and most people with Chlamydia have no symptoms, so many infections are never found.
- A test from 14 days after sex you are worried about gives you an answer you can rely on. Results arrive within two working days of your sample reaching the laboratory, whether you test at a clinic or with a home test kit.
The latest national figures on sexually transmitted infections (STIs) show that Chlamydia diagnoses in England fell again in 2025, following a fall the year before.
The UK Health Security Agency recorded 151,163 Chlamydia diagnoses in 2025, a decrease of 10.3% on the year before. Even so, Chlamydia remains the most commonly diagnosed STI in the country.
At Better2Know, we talk to a lot of people who see headlines like this and wonder whether they still need to test. The answer is yes. In this blog, we’ll look at what the fall means, why testing still matters, and what to do if you are worried. Keep reading to find out more.
What changed last year?
Chlamydia is a bacterial infection passed on through vaginal, anal and oral sex, and by sharing sex toys. It affects people of any age, but rates of STIs in England remain relatively high in young people aged 15 to 24.
Most of the fall was among young people. Diagnoses in this age group dropped by 12.8%, and the fall in young women was larger still.
Testing fell too. The number of Chlamydia tests carried out in young women dropped by 9.4%, with the biggest drop in tests ordered online.
Does this mean there is less Chlamydia about?
Possibly, but not necessarily. A fall in diagnoses can mean fewer people have the infection. It can also mean fewer people are being tested, so fewer infections are found.
When diagnoses in young people fell sharply in 2024, the agency looked into why. It found that both explanations fit the data: there may be fewer infections among young people since the pandemic, or fewer young people at higher risk may be getting tested. It could be a mix of the two.
England is not alone. Across the EU and EEA, the rate of reported Chlamydia cases fell by 10% in 2024. Differences in testing between countries are thought to shape the reported numbers more than real differences in infection.
Why does testing still matter?
Chlamydia is often called a silent STI, because most people who have it feel completely well. Without a test, you can carry it for months and pass it on without knowing.
Left untreated, Chlamydia can lead to pelvic inflammatory disease, ectopic pregnancy and problems with fertility. Our guide to whether Chlamydia can make you infertile explains how.
The good news is that it is simple to test for and straightforward to treat with a short course of antibiotics. A lower national figure doesn’t change your own risk after a new partner or sex without a condom. Only a test can tell you where you stand.
What should I do if I’m worried?
- Test from 14 days after the sex you are worried about. This is the window period for all Better2Know Chlamydia tests, and our guide to when you can test for Chlamydia explains the timing.
- Test straight away if you have symptoms, or if a partner has tested positive and you first had sex with them more than 14 days ago. There is no need to wait, and you can tell us when you book.
- Condoms, or a break from sex, protect a partner until you have your result. You can pass Chlamydia on even when you feel fine.
- Testing with each new partner gives you peace of mind. It also means any infection is found and treated early.
Take control of your health
The same encounter that passes on Chlamydia can expose you to Gonorrhoea and Syphilis as well. From 14 days, our Peace of Mind screen checks for all three in one visit or one home test kit. Syphilis can take longer to show up, so a negative Syphilis result at 14 days needs a follow-up test later on, and our team can tell you when.
You can test at one of our private clinics across the UK, where most appointments take around 10 to 15 minutes and many are available the same or next day, or order a home test kit, which arrives in plain packaging with free return postage. If you need a quicker answer, our instant test for Chlamydia and Gonorrhoea gives a result in the clinic in under 30 minutes. It is less sensitive than a laboratory (PCR) test, especially if you have no symptoms, so a negative result is best confirmed with a laboratory test.
Results are reported to your secure online patient area within two working days of your sample reaching the laboratory. If anything is found, we can arrange a doctor’s consultation and help you get treatment. Everything is confidential and anonymous, and our Patient Care Team is available 24/7 on 020 7099 0955.
Fewer diagnoses is welcome news, but it is not a reason to skip a test. Take control of your sexual health and book a confidential Chlamydia test with Better2Know, online or by phone.
Medical review. This article was medically reviewed by Dr Steve Chapman, a doctor with a wealth of clinical experience in the field of STIs, on 15 October 2026. Better2Know content is reviewed for clinical accuracy before publication and updated when guidance or surveillance data changes. It is general information and not a substitute for personal medical advice.
