Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link
Quick Facts

Trichomonas Vaginitis


The Manual's Editorial Staff

Last full review/revision Jun 2021| Content last modified Jun 2021
Click here for the Professional Version
Get the full details
Topic Resources

What is Trichomonas vaginitis?

Trichomonas vaginitis is an infection in your vagina. Your vagina connects your uterus (where a baby grows when you're pregnant) to the outside of your body. Some people call it the birth canal. Your vulva is the area between your legs on the outside of your body. Many people mistakenly refer to the vulva as the vagina.

  • The most common cause is having sex with an infected partner

  • The infection can be in your body for weeks or months before you get any symptoms

  • When you do get symptoms, you may have a lot of green or yellow vaginal discharge (thick fluid that comes out of your vagina) that looks bubbly or smells fishy—if this happens, see your doctor

  • Untreated trichomonas can cause serious problems, especially if you get this infection while pregnant

  • To help prevent this infection, don't have sex or, if you have sex, use a condom

Internal Female Genital Organs

Internal Female Genital Organs

What causes Trichomonas vaginitis?

You get trichomonas by having sex with a partner who has trichomonas. Your partner may not have any symptoms of trichomonas but can still give you the infection.

What are the symptoms of Trichomonas vaginitis?

The main symptom is vaginal discharge that may:

  • Be green or yellow in color

  • Look bubbly or foamy

  • Smell fishy

  • Happen in large amounts

You may also have:

  • Itching, redness, or pain around the opening to your vagina

  • Pain during sex or when you urinate (pee)

How can my doctor tell if I have Trichomonas vaginitis?

Your doctor will suspect trichomonas based on your symptoms. To tell for sure, your doctor will do a pelvic exam. During a pelvic exam, your doctor looks at your vulva and inside your vagina. In order to see inside, your doctor will hold your vagina open with a small instrument called a speculum. During the exam, the doctor will use a cotton swab to take a sample of discharge from your vagina and test it.

If a test done on a child shows infection, doctors will check the child for signs of sexual abuse.

How do doctors treat Trichomonas vaginitis?

  • You'll be prescribed an antibiotic to take by mouth

  • You shouldn't drink alcohol for at least 72 hours after you take the antibiotic—it can make you feel sick, vomit, and have a headache

  • Doctors will also tell you to use condoms during sex or to not have sex until your infection has gone away

Your sex partners should be checked by a doctor, who will prescribe the same antibiotic. Men usually need to take the antibiotic for 1 week.

How can I prevent Trichomonas vaginitis?

To reduce your risk of getting this infection, always use a condom during sex.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Test your knowledge

Loss of Smell
Anosmia is the total loss of smell. Most people with anosmia can taste sweet, sour, salty, and bitter substances but cannot distinguish among specific flavors. This is because the sense of smell makes it possible to distinguish among flavors, not taste receptors as many people erroneously believe. Which of the following is NOT a common cause of anosmia?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID