Is a UTI an STI? How to tell the difference

No. A urinary tract infection (UTI) is usually caused by bacteria from poo getting into the urinary tract. It isn’t one of the infections the NHS lists as STIs.

But having sex is one of the ways these bacteria can get in, so a UTI can follow sex. That’s why the NHS suggests peeing as soon as you can after sex if you get UTIs. Read more in “Is a UTI caused by sex?”

A UTI can affect your bladder (cystitis), your urethra, the tube you pee through (urethritis), or your kidneys. Anyone can get one, but they’re particularly common in women, whose shorter urethra makes it easier for bacteria to reach the bladder.

Symptoms of a UTI include:

• pain or a burning feeling when you pee
• needing to pee more often, suddenly or during the night
• cloudy pee, or blood in your pee
• pain low in your tummy, or in your back just under the ribs
• a high temperature, feeling hot or cold and shivery, or a very low temperature
• feeling tired or weak

Several STIs can cause pain or burning when you pee, including:

• Chlamydia
• Gonorrhoea
• Trichomonas
• Genital Herpes
• Mycoplasma genitalium

Many people with these infections have no symptoms at all. Most people with Chlamydia don’t, for example, so feeling fine doesn’t rule out an STI. Read more in “Why does it hurt when I pee?”

The symptoms overlap, so you can’t always tell from symptoms alone. But some signs point more one way than the other.

Signs that point more to an STI

• unusual discharge from your vagina, penis or bottom
• blisters, sores or warts around your genitals or bottom
• bleeding after sex or between periods
• pain during sex
• pain or swelling in your testicles

Signs that point more to a UTI

• needing to pee suddenly or urgently, or during the night
• cloudy pee
• pain in your back, just under the ribs

Needing to pee often can happen with both, for example with Trichomonas in men. UK guidance for doctors notes that 75% to 80% of people with vaginal discharge don’t have a UTI, and advises asking about sexual history in sexually active people with urinary symptoms. Read more in “Is it Herpes or a UTI?”

In women

Burning when you pee is often a UTI. But Chlamydia, Gonorrhoea and Trichomonas can all cause it too, sometimes with unusual discharge, bleeding after sex or between periods, or pain in your lower tummy. If you’ve had sex with a new partner, it’s worth testing for STIs as well.

In men

UTIs are less common in men. UK guidance for doctors says to ask about STIs in sexually active men with these symptoms, because urethritis caused by an STI, such as Chlamydia or Mycoplasma genitalium, can feel like a UTI. The NHS also says men with UTI symptoms should get medical advice urgently. In men, a fever with urinary symptoms can mean the infection has spread to the prostate or kidneys.

Yes. UK guidelines mention a study that found a UTI in 6% of men with non-gonococcal urethritis, inflammation of the urethra that’s often caused by Chlamydia or Mycoplasma genitalium.

A UTI test looks for the bacteria that usually cause UTIs, and it doesn’t test for STIs. STIs need their own tests, which can often be done on a urine sample too. So if you’re not sure, you may need both.

Get urgent medical care if you have symptoms of a UTI and:

• you have a high or very low temperature, or feel hot, cold or shivery
• you have pain in your lower tummy or in your back, just under the ribs
• you have blood in your pee
• you’re a man, or are trans or non-binary and were assigned male at birth
• you’re pregnant
• you’re 65 or older, have diabetes or a weakened immune system, or use a catheter
• your symptoms get worse quickly, or don’t improve within 2 days of starting treatment or treating it yourself
• you keep getting UTIs (2 within 6 months, or 3 within 12 months)

In an emergency, call 999, for example if you feel confused or drowsy, find it hard to speak, or have sudden, severe pain in a testicle.

To lower your risk of UTIs, the NHS suggests:

• peeing as soon as you can after sex
• washing the skin around the vagina with water before and after sex
• wiping from front to back after going to the toilet
• drinking plenty of fluids, particularly water
• not using condoms, a diaphragm or a cap with spermicidal lube on them

Peeing after sex doesn’t protect you from STIs, though. Condoms lower your risk, and regular testing finds infections early. Read more in “Does peeing after sex really prevent STIs?”

If you have symptoms and you’re not sure whether it’s a UTI or an STI, you can test for both. Better2Know offers:

• Comfort Screen: tests a urine sample for 8 infections, including Chlamydia, Gonorrhoea, Trichomonas and Mycoplasma, from 14 days after sex, with results in 2 days at a clinic, or order a Comfort Screen home test.
• Urine Analysis: Culture and Microscopy: our UTI test checks your urine for a bacterial infection and shows which bacteria are causing it, so the right antibiotic can be chosen, with results in 2 days. You can take it at one of our clinics or with a home test kit.
• Full Screen: tests for 7 infections, including HIV and Syphilis, from 28 days after sex, with results in 3 days. If you test before 45 days, a negative HIV result needs a repeat test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test.

Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Can you get a UTI from sex?

Yes. Sex is one of the ways bacteria can get into the urinary tract. Peeing as soon as you can after sex may help lower the risk.

Will a UTI test show an STI?

No. A urine culture looks for the bacteria that usually cause UTIs. STIs need their own tests, which can often be done on a urine sample too. Read more in “How to take a urine sample for a home test”

Can a UTI go away on its own?

Sometimes. The NHS says a doctor may suggest waiting 48 hours before taking antibiotics, in case your symptoms clear on their own. Get urgent medical care if your symptoms get worse, or you have a fever or back pain.

A UTI isn’t an STI, but the two can feel very similar, and you can have both at once. If you’ve had sex with a new partner, or you have discharge, sores or bleeding, test for STIs as well as a UTI, and get urgent help if you have a fever or back pain.

Book a Comfort Screen at a clinic near you or order a home test kit from 14 days after sex. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 20 October 2023 and was last updated on 1 October 2026.

Medical review. This article was medically reviewed by Dr Steve Chapman, Doctor with a wealth of clinical experience in the field of STIs, on 3 February 2026. It is general information and not a substitute for personal medical advice.

Sources

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6. NHS, Gonorrhoea, reviewed 16 December 2024. https://www.nhs.uk/conditions/gonorrhoea/
7. NHS, Trichomoniasis, reviewed 16 July 2025. https://www.nhs.uk/conditions/trichomoniasis/
8. NHS, Genital herpes, reviewed 27 June 2023. https://www.nhs.uk/conditions/genital-herpes/
9. NHS, Testicle pain, reviewed 26 June 2025. https://www.nhs.uk/conditions/testicle-pain/
10. British Association for Sexual Health and HIV, National guideline on the management of non-gonococcal urethritis, 2026. https://www.bashh.org/_userfiles/pages/files/resources/ngu_2026.pdf
11. British Association for Sexual Health and HIV, National guideline for the management of infection with Mycoplasma genitalium, 2025. https://www.bashh.org/_userfiles/pages/files/sonietal2025britishassociationofsexualhealthandhivnationalguidelineforthemanagementofinfectionwith.pdf
12. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines, 2020. https://bhiva.org/wp-content/uploads/2024/10/HIV-testing-guidelines-2020.pdf
13. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://bashh.org/_userfiles/pages/files/syphilis_2024.pdf