STD - Trichomonas  
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Does this describe your symptoms?

  • Seeking information about trichomonas, a sexually transmitted disease (STD)

General Information

  • Trichomonas is caused by the Trichomonas vaginalis protozoa.
  • Trichomonas is a common STD. It has been estimated that there are eight million new cases each year in North America.
  • Trichomonas is treatable with antibiotics.

Typical Symptoms of Trichomonas

  • In women, trichomonas may cause a foul-odored, yellow, sometimes bubbly vaginal discharge. It may also cause vaginal itching and redness, or burning with urination.
  • Some women have no symptoms.
  • Most men with a trichomonas infection have no symptoms. Sometimes there may be a mild burning with urination or a discharge from the penis.

What is a Normal versus Abnormal Vaginal Discharge?

  • Normal: May be clear or white, thin or thick. It is not odorous and there is no itching.
  • Abnormal:
    • Yellow or green vaginal discharge is usually from an infection.
    • A foul-smelling discharge is usually from an infection.
    • A thick, white, itchy, cottage cheese-like non-odorous discharge is often caused by a yeast infection.

Additional Resources

  1. American Social Health Association
  2. Sexually Transmitted Diseases Treatment Guidelines 2002. MMWR. 2002; 51(RR-6):1-80.
  3. Public Health Agency of Canada

If not, see these topics

When to Call Your Doctor

Call Your Doctor Now (night or day) If
  • You were forced to have sex (sexual assault or rape)
  • Yellow or green vaginal discharge occurring with a fever
  • Constant abdominal pain for more than 2 hours
Call Your Doctor Within 24 Hours (between 9 am and 4 pm) If
  • You think you need to be seen
  • Abnormal color of vaginal discharge (i.e., yellow, green, gray)
  • Bad smelling vaginal discharge
  • Blood in vaginal discharge (Exception: normal, regular menstrual period)
  • Burning or pain with urination
Call Your Doctor During Weekday Office Hours If
  • You have other questions or concerns
  • You are worried you might have a sexually transmitted disease
Self Care at Home If
  • No symptoms and you don't think you need to be seen
  • Questions about trichomonas

  1. How is trichomonas transmitted?
    • Trichomonas is spread by sexual intercourse (vaginal).
    • Some women and many men do not have symptoms when they are infected. As a result, trichomonas can be passed along with neither sexual partners knowing that it is occurring.
  2. How long does it usually take for symptoms to appear once one is exposed?
    • The incubation period is 4 days to 4 weeks.
  3. How can I get tested for trichomonas?
    • Inspection of a sample of the vaginal discharge under the microscope.
    • May also be found on a Pap smear.
  4. Is there treatment for trichomonas?
    • Antibiotic therapy is needed. A person with trichomonas is contagious until he or she has been treated.
    • Sexual partners should also be evaluated and treated.
  5. STD National Hotline
    • The CDC National STD Hotline provides information on sexually transmitted diseases (STDs), such as chlamydia, gonorrhea, HPV/genital warts, herpes, and HIV/AIDS. Specialists can provide general information, referrals to local clinics, and written materials about STDs and disease prevention.
    • Toll-free number (English): (800) 227-8922
    • Toll-free number (Spanish): (800) 344-7432
    • Their website is at:
  6. Pregnancy test, when in doubt:
    • If there is any possibility of pregnancy, obtain and use a urine pregnancy test from the local drug store.
    • Follow the instructions included in the package.
  7. Call Your Doctor If:
    • Pregnancy test is positive or if you have difficulties with the home pregnancy test
    • Discharge from penis or unusual vaginal discharge
    • You become worse

And remember, contact your doctor if you develop any of the "Call Your Doctor" symptoms.

Disclaimer: This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.

Author and Senior Reviewer: David A. Thompson, M.D.

Last Reviewed: 9/15/2011

Last Revised: 1/9/2010

Content Set: Adult HouseCalls Symptom Checker

Copyright 2000-2012. Self Care Decisions LLC; LMS, Inc.