Trichomoniasis: Symptoms, Diagnosis And Treatment For The Lesser-Known STI

Smelly discharge and pain while urinating are key signs.

Trichomoniasis, or trichomonas vaginalis (TV), is a little-known STI that’s caused by a tiny parasite.

In women, who more commonly experience it, the infection can be found in the vagina and the urethra, while in men it’s found solely in the urethra.

It can be spread through unprotected vaginal sex and possibly through sharing sex toys if they aren’t washed or covered with a new condom between use.

“We don’t know if the infection can be spread between women by rubbing vulvas together or by transferring discharge from one vagina to another on the fingers,” reads guidance from sexual health charity FPA.

While TV isn’t nearly as common as chlamydia, genital warts or gonorrhoea, it’s still worth knowing about. Here, we speak to experts about what symptoms to look out for, as well as diagnosis and treatment.


“With TV, as with many other STIs, around half of people infected with it won’t have any noticeable signs or symptoms,” explains the chief executive of FPA, Natika Halil.

For the other half of the population who do experience symptoms, women might notice signs such as soreness around the vagina or pain when urinating or having sex.

They may also notice a change in their vaginal discharge, for example it may become thick, thin or frothy and yellow-green in colour. Other women may produce more discharge than normal, which might have an ‘unpleasant fishy smell’.

In men symptoms include thin and white-coloured discharge coming from the penis, pain when urinating or ejaculating, and an inflamed foreskin.

“To prevent the parasite from passing from person to person, men should wear a condom and an oral dam should be used for oral sex,” explains Dr Helen Webberley, GP for Oxford Online Pharmacy.


If you experience any of the symptoms above, it’s worth booking an appointment at your local sexual health clinic or with your GP to get to the bottom of the matter.

“Ultimately, the only way to be sure if you have the infection is to have a test, which will usually involve taking a swab,” explains Halil.

“It’s nothing to worry or be embarrassed about. A test will usually be offered to women who have signs and symptoms of TV or men who have signs and symptoms not caused by other infections such as chlamydia and gonorrhoea.

“If a sexual partner has TV you’ll also be offered a test.”

For those who might be limited on time, Dr Webberley adds that you can buy STI tests via an online pharmacy which you can then do at home.

“This can be a great option if anonymity is a factor,” she adds. “Although if you do test positive, full STI screening is recommended and treatment should be sought in clinic.”


The sexually transmitted infection can be easily treated with a course of antibiotics and “it’s very unusual for it to cause serious complications”.

That being said, it’s important that pregnant women who might have it are properly diagnosed and treated, as the infection can cause problems with a pregnancy.

According to the NHS, the infection can cause an unborn baby to be either born prematurely (before the 37th week of pregnancy) or have a low birth weight.

Halil adds: “It’s not thought to affect your future fertility. However, as with all STIs, prevention is much better than a cure so looking after your health by using condoms and getting regular STI tests is advised.”