Trichomoniasis is a sexually transmitted infection (STI).


A parasite passes between people during sex.

Risk Factors

Your risk may be higher if you:

  • Have many sex partners
  • Do not use condoms during sex
  • Have had STIs before


You may not always have symptoms. Symptoms appear in women more often than men. If you do have them:


  • A foul-smelling, greenish-yellow, or gray discharge from the vagina
  • Pain, itching, or burning of the genitals
  • Bleeding after sex

Infection Site in Women

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  • Discharge from the penis
  • Itching or pain
  • Pain when passing urine
  • Pain in the testicles or scrotum

Infection Site in Men

Male Urethtra
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Your doctor will ask about your symptoms, and sexual and health history. Your doctor will check the pelvic area for signs of infection.

Testing involves:

  • Women—testing fluid or discharge from the vagina
  • Men—testing urine, semen, or discharge from the penis

A lab will check the samples for the parasite.


Antibiotics treat the infection. You should not have sex until you stop treatment and your symptoms are gone.

Part of care involves talking to your sexual partners. They may need healthcare even if they don’t have symptoms.


To lower your chances of STIs:

  • Always use condoms when you have sex.
  • Only have sex with one person.


Centers for Disease Control and Prevention
The American Congress of Obstetrics and Gynecology


Sex & U—The Society of Obstetricians and Gynaecologists of Canada
The Sex Information & Education Council of Canada


2015 Sexually transmitted diseases treatment guidelines. Centers for Disease Control and Prevention website. Available at: January 25, 2017. Accessed May 8, 2018.
Sexually transmitted diseases. National Institute of Allergy and Infectious Diseases website. Available at: Accessed May 8, 2018.
Trichomoniasis. Centers for Disease Control and Prevention website. Available at:
...(Click grey area to select URL)
Updated April 28, 2015. Accessed May 8, 2018.
Trichomoniasis. EBSCO DynaMed Plus website. Available at: . Updated April 24, 2018. Accessed May 8, 2018.
Last reviewed May 2018 by David L. Horn, MD, FACP
Last Updated: 5/11/2018

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