Also Known As
Formal Name
Trichomonas vaginalis
This article was last reviewed on
This article waslast modified on 18 March 2019.
At a Glance
Why Get Tested?

To diagnose an infection with Trichomonas vaginalis

When To Get Tested?

If you have symptoms of infection or have had unprotected sex and are concerned you may be at risk of an STI (sexually transmitted infection).

Sample Required?

A swab of secretions taken from the vagina in women or the urethra in men. A urine sample can also be used in men.

Test Preparation Needed?


On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

The test is looking for infection by Trichomonas vaginalis, a sexually transmitted, microscopic parasite that causes vaginal infections in women and urethritis in some men.

How is the sample collected for testing?

In women, a swab of secretions is collected from the vagina. In men, a swab is inserted into the urethra of the penis.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

Accordion Title
Common Questions
  • How is it used?

    The secretions collected on the swab are examined under a microscope to detect the presence of Trichomonas vaginalis.

  • When is it requested?

    Your doctor may request the test if you complain of symptoms, such as vaginal discharge or pain on urination or have recently had unprotected sex. If you have an infection with another sexually transmitted infection, your doctor might test for trichomonas as well.

  • What does the test result mean?

    A positive test indicates an active infection that requires treatment with a course of antibiotics. You will usually have to take the antibiotic twice a day for 5-7 days.

  • Is there anything else I should know?

    An infected person is at greater risk of getting other sexually transmitted infections, so the doctor may also test for these. It is important that your current and other recent sexual partners are made aware, so that they can also get tested.

    Trichomonas infection can affect pregnancy, contributing to premature birth and low birth weight. You should inform your doctor if you may be pregnant. The doctor may medically manage a woman who is infected and in her first three months of pregnancy differently.

  • What are the symptoms of a trichomonas infection?

    In women, the most common symptoms include a foul-smelling green discharge from the vagina and itching or redness in and around the vagina. Other symptoms can include abnormal vaginal discharge, an unpleasant fishy smell, pain during urination or when having sexual intercourse. Symptoms for men can include , soreness, swelling or redness around the penis, pain during ejaculation, discharge, increased urination or pain during urination.However, 50% of women and the majority of men with T. vaginalis infections have no symptoms.

  • How is trichomonas transmitted?

    The parasite is transmitted through sexual contact.

  • How is it treated?

    It is usually treated with an antibiotic called metronidazole. All current sexual partners must be treated at the same time or the patient is likely to become re-infected.

  • How can it be prevented?
    • Use a latex condom properly, every time you have sexual intercourse, with every partner.
    • If you are infected, your sexual partner(s) should be treated. This will prevent you from getting re-infected.