Trichomoniasis, or trich, is an STI caused by a small parasite called trichomonas vaginalis (TV). It’s usually passed on by having sex without a condom.

How do you get trichomoniasis?

Trichomoniasis is passed on through vaginal sex without a condom. It can also be spread by sharing sex toys. It’s not thought that trich can be passed on through oral or anal sex.

Symptoms of trichomoniasis

A lot of people can have trichomoniasis without having any symptoms. So you might not know you have it. People with vaginas are more likely to have symptoms than people with penises.

The infection can last months or even years, and symptoms can come and go. Symptoms of the infection can develop after about a month and can be similar to other common STIs. They include:

  • unusual discharge from the penis or vagina, this could be discharge that’s a different smell, colour or consistency or more discharge than usual

  • pain when peeing or during sex

  • needing to pee more often than usual

  • soreness, pain or itching around the vagina or head of the penis

If you have any symptoms of trich, you should visit your GP or local sexual health clinic.

Getting tested

You can get a test at a sexual health clinic or at your GP. Current guidelines say you only need a test if you have undiagnosed symptoms, your partner has it, or you live in an area where there are a lot of cases.

If you do need a test, the clinician will examine your genital area and take a sample. If you have a vagina, they’ll take a swab of the area to get a sample. If you have a penis, they’ll ask for a sample of urine. Samples are sent to a lab for testing.

Test results are most accurate 1 to 4 weeks after you’re first exposed to the infection.

There are at-home tests for trichomoniasis available to buy online. With these, you’ll take the sample yourself and send it to a lab for testing.

The test is known as NAAT (nucleic acid amplification tests) and is the most accurate test for trich.

Is trichomoniasis serious?

All sexually transmitted infections can be serious if they’re not treated quickly.

Left untreated, trichomoniasis causes genital inflammation. This increases your chance of getting other STIs, including an increased risk of contracting or transmitting HIV.

Complications are rare, but if you have trich while you're pregnant, it can cause the baby to be born prematurely or have a lower birth weight. If you’re pregnant and have symptoms of trichomoniasis it’s important to seek advice as soon as you can.

For people with vaginas, untreated trichomoniasis cause cervicitis – inflammation of the cervix. Symptoms of cervicitis, if they appear, can be bleeding between periods, pain during or after sex and abnormal discharge.

How to avoid trichomoniasis

The best protection from getting or passing it on is to use condoms for sex and on sex toys. You can get free condoms at sexual health clinics.

Avoid sex for 7 days from when you start treatment, as it takes 7 days to clear the infection.

Regular testing helps reduce the spread of STIs. We recommend you test at least once a year. If you regularly have sex with new partners, we recommend testing every 3 months.


Trichomoniasis is unlikely to go away without treatment but it’s usually very treatable with antibiotics.

If you’re still getting symptoms once your treatment is finished though, you may need more tests to make sure they’re not being caused by another STI.

It's recommended you do a test 4 weeks after completing treatment to check the infection has cleared. This is known as a test of cure.

Telling your partners

If you have trichomoniasis, you should tell your partner and anyone you've had sexual contact with in the last 3 months. They may have trichomoniasis without knowing it, so it’s important they get a test, and treatment if needed.

When you get treated for trichomoniasis, the sexual health service should offer to help you with telling your partners. They can help you do this anonymously, usually through a text message. Doing this means you can let partners know they’ve had contact with an infection, without giving them your name.

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