About trichomonas

Trichomonas is an STI caused by a tiny organism called Trichomonas vaginalis.

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What is it?

Trichomonas is also called trichomoniasis or "trich". It’s an STI caused by a tiny organism called Trichomonas vaginalis. It’s more commonly diagnosed in women than men and is usually easy to cure with antibiotics. Although symptoms vary, most people who have trichomonas cannot tell they have it.

The CDC estimates that there were more than two million trichomoniasis infections in 2018. Only about 30% develop any symptoms and older women are more likely than younger women to have the infection.

How is it spread?

Sexually active people can catch it by having sex without a condom with a partner who has trichomonas. During sex, the parasite usually spreads from a penis to a vagina, or from a vagina to a penis. It can also spread from a vagina to another vagina.

In women, the infection is most commonly found in the vulva, vagina, cervix, or urethra. 

In men, the infection is most commonly found inside the penis (urethra). 
People with trichomonas can pass the infection to others, even if they do not have symptoms.


Many people with trichomonas won’t have any symptoms.

If symptoms do appear, it’s usually within a month of being infected.

In women

Many women have trichomonas without symptoms, but if symptoms do occur, they may include:

  • Being sore or itchy in and around the vagina.
  • Increased vaginal discharge that is unusual for you. It may be frothy or yellow and often smells bad.
  • Pain when you pee.

In men

It is rare for men to get symptoms of trichomonas, but if they do get symptoms, these may include:

  • Discharge from the tip of the penis, which may be thin and whitish.
  • Pain or a burning feeling when you pee.
  • A red, sore, or swollen foreskin.

Diagnosis (testing)

The only way to find out if you have trichomonas is to get tested. 

If trichomonas is not treated, it’s unlikely to cause any serious health problems, but any symptoms are unlikely to go away on their own. Also:

  • Until the trichomonas has gone away you can pass it on to other people.
  • People with trichomonas or other STIs may be more likely to get or pass on HIV.

It’s a good idea to get tested for STIs at least once a year and whenever you have a new sexual partner.

Our trichomonas tests are only for people with no symptoms.

Men need to give a urine sample to be tested for trichomonas.

Women need to swab the vagina to be tested for trichomonas. This is simple to do. We’ll send you a swab and some easy-to-follow instructions.

If it’s less than 4 weeks since you might have been exposed to trichomonas, you can still do a test now, but you may need another test later.

If you have any symptoms, get tested at a sexual health service as soon as possible.

What if I get a positive trichomonas result?

Trichomonas is common and easy to cure.

If your trichomonas test is positive, it’s important to get treated with as soon as possible.

Your current or recent sexual partners will need to be tested for trichomonas and may need treatment.

Don’t have any sex until 7 days after both you and your sexual partner(s) have finished all treatment.


The recommended first-line treatment for trichomonas is metronidazole. Treatment reduces symptoms and signs of trichomoniasis and might reduce transmission. Your healthcare provider will advise you to not have sex again until you and your sex partners have completed treatment and any symptoms have gone. Because of the high rate of reinfection among women treated for trichomonas, retesting for trichomonas is recommended approximately 3 months after initial treatment for all sexually active women.

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Trichomonas is an STI caused by a tiny organism called Trichomonas vaginalis.