Thousands of women are mistaking this common STI for period pain

| Assistant Lifestyle Editor Published September 24, 2026 5:54pm Updated September 24, 2026 5:54pm Stomach cramps aren’t always caused by your cycle (Picture: Getty Images) Period pain is something many women have learned to ignore, assuming it’s nothing more than a natural (albeit uncomfortable) process. But according to Dr Asiya Maula, GP at The Health Suite in Leicester, your menstrual cycle isn’t always the cause of cramps and mid-month spotting — it could, in fact, be the UKs most commonly-diagnosed STI. ‘The frustrating thing about chlamydia is that it doesn’t announce itself,” says Dr Maula. ‘Patients come in describing period pain that’s a bit heavier or lasts a bit longer than usual, or spotting between periods that they’ve just learned to live with. ‘Most of the time it’s nothing sinister. But every so often, it’s chlamydia, and they have no idea.’ While chlamydia doesn’t always show symptoms, when it does, they’re typically subtle, and easily mistaken for everything from a UTI to stress. Chlamydia is the UK’s most commonly-diagnosed STI (Picture: Getty Images/Science Photo Libra) And to make it even trickier to properly diagnose and treat, warning signs can come and go. ‘Many people assume there isn’t anything to worry about if the pain or discomfort subsides after a few days, but in reality the infection is still there,’ Dr Maula continues. He warns this is ‘one of the more worrying aspects’, as leaving chlamydia untreated can lead to pelvic inflammatory disease (PID), one of the leading preventable causes of infertility and a major risk factor for ectopic pregnancy. Ask Metro Use AI to go deeper into the stories you care about – powered by Metro and trusted publications. Dr Maula continues: ‘PID can develop silently too. Some women don’t find out anything was ever wrong until years later, when they’re trying to conceive and struggling.’ Regular testing is key (Picture: Getty Images) None of this means you need panic, though — in most instances, it really is just that time of the month. ‘Period pain is incredibly common and has lots of causes, most of which have nothing to do with an STI,’ adds the GP. ‘This isn’t about scaring people, rather it’s about knowing when pain isn’t “just” period pain.’ If in doubt, get checked out. Chlamydia symptoms Regular sexual health screening is key with chlamydia, as in anywhere between 50% and 80% of cases, it’s asymptomatic. When it does show symptoms however, they tend to show from one week to a month after infection, and often look different in men and women. For anyone with a vagina, the STI may show up as: Unusual vaginal discharge Bleeding after sex or between periods A burning sensation when peeing Lower stomach pain Pain during sex or bleeding afterwards Bleeding between periods For anyone with a penis, symptoms include: White cloudy or watery discharge from the tip of the penis Burning and itching around the testicles and penis Testicle swelling and pain A burning sensation when peeing Regardless of your gender, because chlamydia can impact other parts of your body that come into contact with semen or vaginal fluid, it may also present with: Anal pain, bleeding or discharge A sore throat Eye redness, pain or discharge If you think you may have chlamydia or have had unprotected sex, the NHS recommends visiting your local sexual health service for a test. Deals of the Day This new Cricut gadget turns your favourite photos into stickers in minutes From kitchen hatches to burgundy walls – the biggest home trends for 2027 Oodie’s cosy blanket sale has arrived just in time for Christmas shopping Save over £700 on Simba's top-rated mattresses in this limited-time sale Topman’s new-season collection has arrived and prices start at just £10 Chlamydia is easy to treat with antibiotics — and the sooner you do so, the easier it is to avoid additional complications. Do you have a story you’d like to share? Get in touch by emailing MetroLifestyleTeam@metro.co.uk Arrow MORE: Women in Europe won’t have to talk about their ‘shame lips’ anymore Arrow MORE: Cancer-causing ‘forever chemicals’ found in blood of villagers living near factory Arrow MORE: ‘I was warned my baby wouldn’t survive birth – then she gave me a sign in a scan’ The Slice Your free newsletter guide to the best London has on offer, from drinks deals to restaurant reviews.