Is a UTI caused by sex? Why it happens and how to lower the risk

Sex can trigger a UTI, but it doesn’t give you one in the way it gives you an STI. A UTI (urinary tract infection) is usually caused by bacteria from your own gut getting into the urethra, the tube that carries pee out of the body. NHS inform, Scotland’s health information service, says this may happen when you wipe your bottom or have sex, but that often it’s not clear why it happens.

So the bacteria are usually your own. NICE, which writes treatment guidance for the NHS, says one type, E. coli, causes 70% to 95% of uncomplicated UTIs.

UK bodies that name sex as a trigger:

• the British Association of Urological Surgeons lists sexual intercourse among the risk factors for a urine infection
• NICE says some people, mainly women, can identify triggers, such as sex, that often bring on a UTI

In a US study of 482 women aged 18 to 30, having sex more often, having a new sexual partner in the past year and using spermicide were each linked with repeated UTIs.

UTIs are common whether or not sex is involved. In a survey of adult women in England, over a third said they’d had at least one.

Mostly because of where everything is. The NHS says women have a shorter urethra than men, which means bacteria are more likely to reach the bladder or kidneys. A woman’s urethra is also closer to the anus than a man’s, and the gut is where the bacteria come from.

Some things that go with sex raise the risk further:

• Spermicide: the NHS lists using spermicide with contraception among the things that increase the risk of bacteria getting into the bladder. That includes condoms, diaphragms and caps with spermicidal lubricant on them. A US study found that the more often women used spermicide-coated condoms, the higher their odds of a UTI.
• Diaphragms and caps: the NHS lists UTIs among their side effects.
• A new partner, or having sex more often: both were linked with repeated UTIs in the study of women aged 18 to 30.

Plenty of risks have nothing to do with sex. The NHS list includes pregnancy, having been through the menopause, not drinking enough fluids, kidney stones, a catheter and a weakened immune system.

No. A UTI isn’t an STI, and it isn’t passed from one person to another. Brook, the sexual health charity, says cystitis is usually caused by a bladder infection and is not a sexually transmitted infection, and that you can’t pass a UTI on to your partner.

Brook does say it’s wise to wait until a UTI has cleared before having sex again, because sex may be uncomfortable and can aggravate your symptoms.

What can be passed on is an STI, and several of them feel just like a UTI. That’s why a UTI that appears after sex with a new partner is worth a closer look.

You can’t always tell from symptoms, because several STIs cause the same burning when you pee. The NHS lists these symptoms of a UTI:

• pain or a burning feeling when you pee
• needing to pee more often than usual, including at night
• needing to pee suddenly or more urgently than usual
• pee that looks cloudy, or has blood in it
• lower tummy pain, or pain in your back just under the ribs
• a high temperature, or feeling hot, cold or shivery

The NHS also lists pain or burning when you pee as a symptom of Chlamydia, Gonorrhoea, trichomoniasis and genital Herpes. Signs that point more towards an STI include:

• discharge from the vagina or penis that isn’t normal for you. The UK Health Security Agency’s guide for doctors says 75% to 80% of people with vaginal discharge won’t have a UTI
• blisters or sores around your genitals, which can be genital Herpes
• bleeding after sex or between periods, which can be a symptom of Chlamydia

Many STIs cause no symptoms at all, the NHS says, and the only way to know for sure is to get tested. Read more in “Is a UTI an STI? How to tell the difference”.

Men can get UTIs, but less often than women, and UK guidance treats their symptoms differently.

• Treatment: NICE says men with a bladder infection should be offered antibiotics straight away, with a urine sample sent to a laboratory first. The course is 7 days, against 3 for women, because men are more at risk of complications.
• STIs: the UK Health Security Agency’s guide tells doctors to ask sexually active men with urinary symptoms about their sexual history, with STIs such as Chlamydia and Gonorrhoea in mind.
• Urethritis: the same guide tells doctors to consider urethritis, inflammation of the urethra, which can follow sex, irritants or an STI. The NHS says urethritis is usually caused by an STI such as Chlamydia.

So if you’re a man and it burns when you pee after sex, an STI test belongs alongside a UTI test. The NHS also includes being a man in its list of reasons to get medical help urgently for UTI symptoms.

Peeing soon after sex, drinking enough and avoiding spermicide are the main things UK guidance suggests. Here’s what’s suggested, and how good the evidence is for each one.

The first version of this article said to pee before sex as well as after. The NHS, NICE and the British Association of Urological Surgeons only mention peeing after sex, so we’ve taken that out.

The NHS adds that cranberry products and D-mannose can contain a lot of sugar, that cranberry products should be avoided if you take warfarin, and that it’s best to speak to a doctor before taking either during pregnancy.

Peeing after sex doesn’t protect you against STIs. Read more in “Does peeing after sex really prevent STIs?”

With self-care for mild symptoms, and a short course of antibiotics when they’re needed. The NHS says UTIs may be treated with antibiotics, but they’re not always needed.

• Self-care: the NHS suggests paracetamol for pain and a high temperature, rest, and enough fluids that you pass pale pee regularly during the day. It also suggests avoiding drinks that may irritate your bladder, such as fruit juices, coffee and alcohol.
• A pharmacist: in England, women aged 16 to 64 who aren’t pregnant or breastfeeding can be treated for a UTI by a pharmacist. The NHS says a pharmacist can give the same medicines as a doctor.
• Antibiotics: NICE recommends a 3-day course for women who aren’t pregnant, and 7 days for men and during pregnancy.
• Waiting: the NHS says a doctor may ask you to wait 48 hours before starting antibiotics, in case your symptoms go away on their own.

A UTI in pregnancy is handled differently. NICE says pregnant women should be offered antibiotics straight away, and a urine sample is sent to a laboratory first.

NICE counts UTIs as recurrent when you’ve had 2 or more in 6 months, or 3 or more in a year. The NHS says that’s the point to see a doctor.

For people whose UTIs follow a trigger such as sex, NICE sets out what a doctor can offer:

• Everyday measures first: the ones in the table above.
• Vaginal oestrogen: for women around or after the menopause, if everyday measures haven’t worked.
• A single dose of an antibiotic: to take when you’re exposed to the trigger, if the other options haven’t worked or aren’t suitable. NICE’s evidence includes one trial in which a single dose taken straight after sex worked as well as a daily dose, though NICE rated that evidence as low quality.
• Methenamine hippurate: a medicine that, since December 2024, NICE has said doctors can consider as an alternative to daily antibiotics.

The NHS says a doctor may also prescribe a low-dose antibiotic to take for up to 6 months, or refer you to a specialist.

NICE warns that long-term antibiotics carry a risk of resistance, which means they may work less well in the future. It says people taking them to prevent UTIs should be reviewed within 6 months.

Most UTIs are mild, but an infection that reaches the kidneys can become serious. The NHS says a kidney infection can cause sepsis if it’s not treated.

The NHS’s list of reasons to get medical help urgently, if you think you have a UTI, includes:

• you have a very high or low temperature, feel hot or cold, or are shivering
• you have pain in the lower tummy, or in your back just under the ribs
• you have blood in your pee
• your symptoms get worse quickly, or don’t improve within 48 hours
• you’re pregnant
• you’re a man
• you’re aged 65 or older, or it’s a child aged 15 or younger
• you have diabetes, a weakened immune system or a catheter

Call 999 if you or your child are confused, drowsy or have difficulty speaking.

The NHS says blood in your pee isn’t usually anything serious, but it must always be checked. Read more in “Is blood in urine a symptom of an STI?”

A urine test for a UTI doesn’t check for STIs, and an STI test doesn’t check for a UTI. If your symptoms followed sex, you may want both. Better2Know offers:

• 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 at a clinic. It’s also available as a home test kit.
• Comfort Screen: tests a urine sample for 8 infections that can cause burning or discharge, 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.
• Full Screen: tests for 7 infections, including HIV and Syphilis, from 28 days after sex, with results in 3 days (5 days for the home test).

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.

Will a UTI go away on its own?

Sometimes. NICE says an uncomplicated bladder infection in a woman who isn’t pregnant can clear by itself. In trials it reviewed, symptoms went completely in about 62% of women who took antibiotics, against about 26% of those given a placebo. A Scottish guideline says that without treatment, burning lasts about 5 days on average.

Is cystitis the same as a UTI?

Cystitis is one kind of UTI. The NHS says UTIs include cystitis, which is a bladder infection, and kidney infections. It also counts urethritis, an infection of the urethra, which is different because it’s usually caused by an STI such as Chlamydia.

Do condoms cause UTIs?

The NHS advice is about spermicide, not condoms themselves. It suggests avoiding condoms, diaphragms and caps with spermicidal lubricant on them. Condoms still protect you against STIs.

Does a UTI mean my partner has an infection?

No. A UTI is usually caused by bacteria from your own gut, so by itself it says nothing about your partner. If you also have discharge or sores, or you have a new partner, an STI test will tell you more.

Sex can set off a UTI, but it doesn’t pass one on, and often there’s no clear reason why one happens. Peeing soon after sex, drinking enough and avoiding spermicide are the measures UK guidance suggests, and if UTIs keep coming back, there are treatments a doctor can offer. Because some STIs feel the same, it’s worth testing for both if your symptoms followed sex with a new partner.

Book a Urine Analysis: Culture and Microscopy test at a clinic near you, or a Comfort Screen from 14 days after sex. Our Patient Care Team is available 24/7 on 020 7099 0955.

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This article originally appeared on 27 November 2020 and was last updated on 5 October 2026.

This article is general information and not a substitute for personal medical advice.

Sources

1. NHS, Urinary tract infections (UTIs), reviewed 11 July 2025. https://www.nhs.uk/conditions/urinary-tract-infections-utis/
2. NHS inform, Urinary tract infections (UTIs), updated 13 February 2023. https://www.nhsinform.scot/illnesses-and-conditions/kidneys-bladder-and-prostate/urinary-tract-infection-uti/
3. NICE, Urinary tract infection (lower): antimicrobial prescribing (NG109), 2018, updated May 2022. https://www.nice.org.uk/guidance/ng109/chapter/Recommendations
4. NICE, Urinary tract infection (lower): antimicrobial prescribing (NG109), summary of the evidence. https://www.nice.org.uk/guidance/ng109/chapter/Summary-of-the-evidence
5. NICE, Urinary tract infection (recurrent): antimicrobial prescribing (NG112), 2018, updated May 2025. https://www.nice.org.uk/guidance/ng112/chapter/Recommendations
6. NICE, Urinary tract infection (recurrent): antimicrobial prescribing (NG112), summary of the evidence. https://www.nice.org.uk/guidance/ng112/chapter/Summary-of-the-evidence
7. British Association of Urological Surgeons, Urinary infection (adult), December 2024. https://www.baus.org.uk/patients/conditions/14/urinary_infection_adult
8. Brook, Cystitis. https://www.brook.org.uk/your-life/cystitis/
9. nidirect, Urinary tract infections in adults, updated 21 February 2023. https://www.nidirect.gov.uk/conditions/urinary-tract-infections-adults
10. Scottish Intercollegiate Guidelines Network, Management of suspected bacterial lower urinary tract infection in adult women (SIGN 160), September 2020. https://www.sign.ac.uk/media/1766/sign-160-uti-0-1_web-version.pdf
11. Scholes D and others, Risk factors for recurrent urinary tract infection in young women, Journal of Infectious Diseases, 2000. https://academic.oup.com/jid/article/182/4/1177/918190
12. Fihn SD and others, Association between use of spermicide-coated condoms and Escherichia coli urinary tract infection in young women, American Journal of Epidemiology, 1996. https://academic.oup.com/aje/article/144/5/512/66628
13. Hooton TM and others, Effect of increased daily water intake in premenopausal women with recurrent urinary tract infections: a randomized clinical trial, JAMA Internal Medicine, 2018. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2705079
14. Hayward G and others, d-Mannose for prevention of recurrent urinary tract infection among women: a randomized clinical trial, JAMA Internal Medicine, 2024. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2817488
15. Williams G and others, Cranberries for preventing urinary tract infections, Cochrane Database of Systematic Reviews, 10 November 2023. https://www.cochrane.org/CD001321/RENAL_cranberries-preventing-urinary-tract-infections
16. UK Health Security Agency and NHS England, Diagnosis of urinary tract infections: quick reference tools for primary care, updated 7 July 2025. https://www.gov.uk/government/publications/urinary-tract-infection-diagnosis/diagnosis-of-urinary-tract-infections-quick-reference-tools-for-primary-care
17. NHS, Side effects and risks of the diaphragm or cap, reviewed 31 January 2024. https://www.nhs.uk/contraception/methods-of-contraception/contraceptive-diaphragm-or-cap/side-effects-and-risks/
18. NHS, Kidney infection, reviewed 13 February 2025. https://www.nhs.uk/conditions/kidney-infection/
19. NHS, Blood in urine, reviewed 25 September 2026. https://www.nhs.uk/conditions/blood-in-urine/
20. NHS, Urethritis, reviewed 10 May 2023. https://www.nhs.uk/conditions/urethritis/
21. NHS, Chlamydia, reviewed 24 October 2024. https://www.nhs.uk/conditions/chlamydia/
22. NHS, Gonorrhoea, reviewed 16 December 2024. https://www.nhs.uk/conditions/gonorrhoea/
23. NHS, Trichomoniasis, reviewed 16 July 2025. https://www.nhs.uk/conditions/trichomoniasis/
24. NHS, Genital herpes, reviewed 27 June 2023. https://www.nhs.uk/conditions/genital-herpes/
25. NHS, Sexually transmitted infections (STIs), reviewed 13 May 2024. https://www.nhs.uk/conditions/sexually-transmitted-infections-stis/
26. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://www.bashh.org/_userfiles/pages/files/syphilis_2024.pdf
27. 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