The truth about Trichomoniasis: symptoms, testing and treatment

Trichomonas is an STI caused by a parasite called Trichomonas vaginalis. In women, it usually infects the vagina and the urethra (the tube you pee through). In men, it usually infects the urethra.

Many people with Trichomonas have no symptoms, so they don’t know they have it. They can still pass it on, and having it once doesn’t stop you getting it again. Read more in “How common is Trichomonas?”

The NHS says you can get or pass on Trichomonas through:

• vaginal sex without a condom
• skin-to-skin contact of the genital area
• sharing sex toys

It can pass between women, for example through sharing sex toys or close genital contact.

The parasite rarely infects the mouth or bottom, so UK guidelines don’t recommend throat or rectal tests for it. Read more in “Can you get Trichomonas without having sex?”

Symptoms can start 5 to 28 days after you’re infected, but sometimes they don’t appear until much later.

Symptoms in women

• yellow-green discharge from the vagina, which may look frothy or smell fishy
• itching, pain, soreness, swelling or redness in or around the vagina
• pain when peeing or having sex
• tummy pain

Symptoms in men

• discharge from the penis
• pain when peeing
• needing to pee often
• pain or soreness in the penis, testicles or bottom, or when you ejaculate

Other infections can cause similar symptoms, so a test is the only way to know what’s causing them. Read more in “Why do I have green discharge coming out of my genitals?”

Trichomonas is tested with a urine sample or a swab, using a sensitive lab test called a NAAT (nucleic acid amplification test).

• For women, UK guidelines say a vaginal swab, which you can take yourself, is the best sample. A urine test picks up about 9 in 10 infections.
• For men, a urine sample or a swab from the penis can be used.

UK guidelines don’t recommend routine Trichomonas tests for people without symptoms, so it isn’t always part of an STI check. Our Full Screen, for example, doesn’t test for it. A test is recommended if you have symptoms such as unusual discharge, or if a partner has Trichomonas, and you can ask for one if you’re worried, even without symptoms.

Trichomonas is treated with antibiotics, usually metronidazole. UK guidelines recommend:

• metronidazole twice a day for 7 days, or a single larger dose as an alternative
• the 7 day course if you’re pregnant
• no alcohol while you take it and for 48 hours after the last dose, as the combination can make you unwell

It’s important to finish the course, even if you feel better. The NHS advises not having sex until at least 1 week after you and your partners have finished treatment, so you don’t pass the infection back and forth. Current partners, and anyone you’ve had sex with in the 4 weeks before your diagnosis, should be tested and treated, even if their test is negative.

If your symptoms don’t go away, see a doctor. You may need another course of antibiotics and a test 4 weeks after you started treatment. If you test positive with Better2Know, our doctors can help you get the treatment you need.

Without treatment, Trichomonas can last for months or years, and you can keep passing it on. The NHS says it can cause serious complications, including:

• a higher chance of getting or passing on HIV (the World Health Organization says it’s linked to about a 1.5 times higher risk of getting HIV)
• a higher chance of getting bacterial vaginosis
• pelvic inflammatory disease (PID), which can lead to pelvic pain, ectopic pregnancy or infertility
• inflammation of the prostate gland (prostatitis)

If you’re pregnant, Trichomonas can cause your baby to be born early or with a low birthweight. Tell your midwife if you have symptoms or think you might have it.

Better2Know offers:

• Trichomonas test: a urine test from 14 days after sex, with results in 5 days. You can book it at one of our clinics or order a home test kit.
• Comfort Screen: if you have discomfort or unusual discharge, it tests a urine sample for 8 infections, including Trichomonas, Chlamydia, Gonorrhoea and Mycoplasma, from 14 days after sex, with results in 2 days, or 3 days for the home test.
• Platinum Screen: tests for 12 infections, including Trichomonas, 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 Trichomonas more than once?

Yes. Having Trichomonas before doesn’t protect you, so you can catch it again, for example from a partner who hasn’t been treated. That’s why partners need treatment at the same time.

Can men get Trichomonas?

Yes. Men often have no symptoms, and many find out they have it when a female partner is diagnosed. It can still cause problems, such as prostatitis, so it’s worth getting tested if a partner has it.

Can Trichomonas go away on its own?

Sometimes, but you can’t rely on it. UK guidelines say around 20% to 25% of infections clear up without treatment. Without treatment, it can last for months or years, so if you have it, treatment is recommended.

Trichomonas is common, often has no symptoms and doesn’t usually go away on its own. It can raise your risk of HIV and cause problems in pregnancy, but it’s treated with antibiotics. If you have symptoms, a simple urine test can tell you. If a partner has been diagnosed, you should be tested and treated, even if your test is negative.

Book a Trichomonas test at a clinic near you or order a home test kit. 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 30 August 2019 and was last updated on 1 October 2026.

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

Sources

1. NHS, Trichomoniasis, reviewed 16 July 2025. https://www.nhs.uk/conditions/trichomoniasis/
2. British Association for Sexual Health and HIV, United Kingdom national guideline on the management of Trichomonas vaginalis, 2021. https://www.bashh.org/_userfiles/pages/files/resources/tv_2021.pdf
3. British Association for Sexual Health and HIV, Summary guidance on testing for sexually transmitted infections, 2023. https://www.bashh.org/_userfiles/pages/files/resources/bashh_summary_guidance_on_stis_testing_2023.pdf
4. World Health Organization, Trichomoniasis, 21 November 2025. https://www.who.int/news-room/fact-sheets/detail/trichomoniasis
5. World Health Organization, Sexually transmitted infections (STIs), 10 September 2025. https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)
6. US Centers for Disease Control and Prevention, About trichomoniasis, reviewed 31 January 2025. https://www.cdc.gov/trichomoniasis/about/index.html
7. Brook, Trichomoniasis, updated 24 September 2026. https://www.brook.org.uk/your-life/trichomoniasis/
8. 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
9. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://bashh.org/_userfiles/pages/files/syphilis_2024.pdf