Trichomonas vaginalis

Trichomonas vaginalis is a sexually transmitted infection (STI). It's sometimes called trichomonas, trichomoniasis or TV. We use the term trichomonas.

This information is about trichomonas, what you can do if you're worried you might have the infection and advice on how to protect yourself and your partners.

Up to half of infected people won’t have any signs or symptoms at all. Men with trichomonas rarely have symptoms. If you get signs and symptoms, they usually show up within a month of coming into contact with trichomonas.

You might notice the following: 

  • Soreness, inflammation (pain, redness or swelling) or itching in and around the vagina. This can cause discomfort when having sex.
  • A change in vaginal discharge. There may be a small amount or a lot, and it may be thick or thin, or frothy and yellow. You may also notice a strong smell that may be unpleasant.
  • Pain, or a burning sensation, when passing urine.
  • A discharge from the penis. This discharge may be thin and whitish.
  • Inflammation of the foreskin (this is uncommon).

How will I know if I have trichomonas?

You need a test to find out if you have trichomonas.

A test for trichomonas is usually offered if:

  • you have signs and symptoms of trichomonas
  • you have signs and symptoms which haven’t been caused by other infections such as chlamydia and gonorrhoea
  • a sexual partner has trichomonas.

You may also be advised to have a test if:

  • you’ve recently had unprotected sex with a new partner
  • you or a partner have had unprotected sex with other partners
  • during a vaginal examination, your doctor or nurse notices an unusual discharge, or the cervix (entrance to the uterus at the top of the vagina) is red and inflamed
  • a sexual partner tells you they have a sexually transmitted infection
  • you have another sexually transmitted infection
  • you’re pregnant or planning a pregnancy.

You could still have trichomonas even if a partner has tested negative. If you have trichomonas, you should be tested for other sexually transmitted infections as you can have more than one sexually transmitted infection at once.

Trichomonas vaginalis is an infection caused by a tiny organism (a living cell) called Trichomonas vaginalis.

It can infect the vagina, the urethra (tube that carries urine out of the body) and under the foreskin of the penis.

The infection is easily passed from one person to another through sexual contact.

Anyone who’s sexually active can get it and pass it on. You don’t need to have lots of sexual partners.

Trichomonas is nearly always passed from one person to another through unprotected (without a condom) vaginal sex. It can also be spread through sharing sex toys if you don’t wash them or cover them with a new condom each time they’re used, but this is rare.

You can’t get trichomonas from anal sex, oral sex (going down, giving head) or from kissing, hugging, sharing cups, plates or cutlery, toilet seats or towels.

How soon after sex can I have a check-up?

You can be checked as soon as you think you might’ve been in contact with trichomonas.

A doctor or nurse can tell you if you need a test.

What does the check-up involve?

There are different ways of testing for trichomonas.

You may be asked to give a urine sample.

  • If you have a vagina, a doctor or nurse may take a swab from the vagina during an internal examination or you may be asked to use a swab yourself.
  • If you have a penis, a doctor or nurse may use a swab to collect a sample from the entrance to the urethra (tube that carries urine out the body) at the tip of the penis.

A swab looks like a cotton bud, but is smaller and rounded. It sometimes has a small plastic loop on the end rather than a cotton tip. It’s wiped over the parts of the body that could be infected and easily picks up samples of discharge and cells. This only takes a few seconds and isn’t painful, though it may be uncomfortable for a moment.

Sometimes your sample can be looked at under a microscope and you can get the result straight away. Otherwise, you may have to wait up to 10 days. Routine blood tests don’t detect trichomonas. If you don’t know if you’ve been tested for trichomonas, just ask.

How accurate are the tests?

The accuracy of trichomonas tests depends on the type of test used and who it’s used on. Tests done on people with male genitals are usually less accurate.

As no test is 100% accurate, there’s a small chance you’ll get a negative result when you do have trichomonas. This is called a false negative result. This can sometimes explain why you might get a different result when you have another test or why you and a partner might get a different test result.

It’s very rare for a trichomonas test to be positive when you haven’t got trichomonas.

Where can I get a check-up?

There are a number of services you can go to. Choose the service you feel most comfortable with. A trichomonas test can be done at:

  • a genitourinary medicine (GUM) or sexual health clinic  
  • some general practices – ask a doctor or practice nurse
  • some contraception clinics and young people’s services.

For information on how to find a service see How to get help with your sexual health.

Will I have to pay for tests?

All tests are free through NHS services. Treatment is also usually free (see Treatment, below).

Will I have to pay for treatment?

Treatment is free unless you go to your general practice where you may have to pay a prescription charge for the treatment.

What's the treatment for trichomonas?

  • The treatment involves taking a course of antibiotic tablets. This may be a single dose or a longer course (up to a week). If you take it according to the instructions it’s at least 90% effective.
  • You’ll be advised not to drink alcohol during the treatment and for 48 hours afterwards. This is because antibiotics used to treat trichomonas react with alcohol and can make you feel very unwell.
  • If there’s a high chance you have the infection, treatment may be started before the results of the test are back. You’ll always be given treatment for trichomonas if a partner is found to have trichomonas.
  • Tell the doctor or nurse if you’re pregnant, think you might be, or are breastfeeding, as this can affect the treatment you’re given.
  • There’s no evidence that complementary therapies cure trichomonas. Complementary therapies are therapies that fall outside of mainstream healthcare.

When will the signs and symptoms go away?

You should notice an improvement in the signs and symptoms within a few days.

If you develop tenderness in your lower abdomen, see your doctor or nurse as there may be other possible causes of the pain.

Do I need to have a test to check that the trichomonas has gone?

If you take the treatment according to the instructions you won’t normally need a follow up test. You should go back to the clinic if:

  • you think you may have come into contact with trichomonas again
  • you had unprotected sex with a partner before the treatment was finished 
  • you didn’t complete the treatment or didn’t take it according to the instructions
  • you vomited after taking the tablets
  • the signs and symptoms don’t go away 
  • your test was negative but you develop signs or symptoms of trichomonas 

In these situations, you may need a repeat test. This can be done one week after the first test. You may need another course of antibiotics, a different treatment, or tests for other infections.

Even if you’ve been treated for trichomonas, it’s possible to become infected again in the future.

You can always go back to the doctor, nurse or clinic if you’ve any questions or need advice on how to protect yourself from sexually transmitted infections

What happens if trichomonas isn't treated?

If you have trichomonas you may be at more risk of becoming infected with HIV if you have sex with someone who’s HIV positive and they’re not on effective treatment. If you’re HIV positive and not on effective treatment then you may be more at risk of transmitting trichomonas to a partner. Effective HIV treatment can suppress HIV in the body (known as having an undetectable viral load) and means HIV can’t be passed on to a partner

Trichomonas may also cause problems with a pregnancy (see Other things to know).

Trichomonas isn't thought to affect your fertility.

Can trichomonas go away without treatment?

Trichomonas can go away without treatment for some people but this can take a long time. If you delay seeking treatment you risk passing the infection on to someone else.

If the test shows that you have trichomonas then it’s very important that your current sexual partner(s) and any other recent partners are also tested and treated.

You may be given a contact slip to send or give to your partner(s) or, with your permission, the clinic can do this for you. This is called partner notification. It can sometimes be done by text message. The message or contact slip will say that they may have been exposed to a sexually transmitted infection and suggest they go for a check-up. It may or may not say what the infection is. It won’t have your name on it, so your confidentiality is protected.

You’re strongly advised to tell your partner(s), but it isn’t compulsory. The staff at the clinic or general practice can discuss with you which of your sexual partners may need to be tested.

How soon can I have sex again?

Don’t have any sexual intercourse, including vaginal, anal or oral sex, until seven days after you and your sexual partner(s) have finished the treatment and any follow-up treatment. This is to help prevent you being re-infected or passing the infection on to someone else.

Will I know how long I've had the infection?

The test can’t tell you how long the infection has been there.

If you feel upset or angry about having trichomonas and find it difficult to talk to a partner or friends, don’t be afraid to discuss how you feel with the staff at the clinic or general practice.

Will trichomonas affect my fertility?

No. There’s no evidence that trichomonas will affect your fertility

What happens if I get trichomonas when I'm pregnant?

Trichomonas may cause problems with a pregnancy. Some research suggests that it could lead to a premature (early) birth or a baby with a low birth weight.

If you’re pregnant, tell the doctor or nurse so that they can discuss your treatment choices with you.

It’s possible to transmit trichomonas to the baby during the birth although this isn’t common.

You can be treated for trichomonas during pregnancy or if you’re breastfeeding. The treatment may affect the taste of breast milk so you may be advised to express and discard your milk until you’ve finished the treatment.

Does trichomonas cause cervical cancer?

No. Trichomonas doesn't cause cervical cancer.

The following measures will help protect you from getting or passing on trichomonas and most other sexually transmitted infections including HIV, chlamydia and gonorrhoea.

  • Use external condoms or internal condoms every time you have vaginal or anal sex. See How to use condoms.
  • If you have oral sex (going down, giving head), use a condom to cover the penis, or a dam (latex or plastic square) to cover the vulva (external female genitals) or the anus.
  • Avoid sharing sex toys. If you do share them, wash them or cover them with a new condom before anyone else uses them.
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This website can only give you general information about sexually transmitted infections. The information is based on evidence-based guidance produced by The British Association for Sexual Health and HIV (BASHH).

Contact your doctor, practice nurse or a clinic if you are worried or unsure about anything.