Trichomoniasis is a sexually transmitted infection (STI) caused by the Trichomonas vaginalis (TV) parasite.

About Trichomoniasis

In women, this parasite mainly infects the vagina and urethra. In men, the infection mostly affects the urethra as well as the head of the penis or prostate gland.

Trichomoniasis can be difficult to diagnose because symptoms are similar to other sexually transmitted infections (STIs).

Signs and Symptoms

Symptoms usually develop within a month of being infected.

Symptoms in women include:

  • Abnormal vaginal discharge
  • Soreness, swelling and itching around the vagina
  • Pain or discomfort when passing urine or having sex

Symptoms in men include:

  • Pain when peeing or during ejaculation
  • Needing to pee more frequently than usual
  • Thin, white discharge from the penis
  • Soreness, swelling and redness around the head of the penis

How is it Transmitted?

Trichomoniasis is caused by the trichomonas vaginalis parasite.

It is usually spread by having sex without using a condom or by unclean sex toys.

Trichomoniasis is not passed on through oral or anal sex.


The best way to prevent trichomoniasis is to have safe sex. Use condoms (male or female) every time you have vaginal or anal sex. Avoid sharing sex toys and if you do share them wash or cover them with a new condom before any else uses them.


Trichomoniasis is unlikely to go away without treatment but it can be usually treated quickly and easily with antibiotics.

Most people are prescribed an antibiotic which you take twice a day, for 5 to 7 days.

If you take your antibiotics correctly, you normally won’t need any follow up tests or examinations.

Any sexual partner you have should also be tested and treated for trichomoniasis.


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Contacting a sexual health service for the first time can be a little daunting, so here are some easy answers to many of the questions you may have.

What should I do if I think I have trichomoniasis?

Call our Helpline on 0300 003 1212

Can I catch trichomoniasis again?

Even if you have recovered from trichomoniasis you will not be immune to the infection and could catch it again. The best way to prevent this is by having safe sex.

How is trichomoniasis diagnosed?

You’ll first need an examination by a doctor or nurse to see the infected area. After this you may need a swab taken from either the vagina or penis. This will be analysed in a laboratory to check for signs of the trichomoniasis infection.