What is trichomoniasis?

Trichomoniasis (also known as trich) is the most common and treatable sexually transmitted disease (STD). It is caused by the germ trichomonas vaginalis and spread through unprotected sex with an infected partner.

Anyone can become infected with trich, but your risk is increased if you have multiple sex partners or have another STD.

Signs and symptoms

Symptoms of trich differ from person to person and from males to females. Infected males usually have no symptoms and do not know they have the infection.

Symptoms may include:

  • Vaginal discharge (females); douching may worsen this symptom
  • Vaginal itching (females)
  • A burning feeling when urinating (males)

Whether you have symptoms or not, if you have trich, you can still spread the infection.

Testing and diagnosis

To diagnose trichomoniasis in females, a cotton swab is briefly placed inside the vagina by you or your healthcare provider. This does not require a pelvic exam. Your healthcare provider will then take that cotton swab and look at it under a microscope to see if any trichomonads are visible.

It is more difficult to test for trich in males. Usually males find out they are infected once a female partner becomes infected.


A medication called metronidazole (Flagyl) will kill the trich and rid your body of the infection. This is usually given as a single dose.

You should make sure your partner gets treated too, regardless of whether or not he or she has symptoms. Even if your partner is not the one who gave the infection to you, you may have passed it along without knowing it. Using condoms or other barrier contraceptives can help prevent the spread of trich.

You should avoid sex until you and your partner are both treated.


Individuals treated for trich usually have a full recovery. However, having trich may increase your chances of getting other STDs, including HIV infection.

If you choose not to be treated for your infection, you may continue to have symptoms such as irregular bleeding and vaginal discharge. You will also continue to be infectious to other sexual partners. 

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