Trichomoniasis (trich) is a sexually transmitted infection (STI) caused by the protozoan Trichomonas vaginalis. Symptoms of trichomoniasis include yellow or greenish discharge, pain and burning with urination, and vulvovaginal (genital) itching.

This infection can affect people of any gender and can be passed from one person to another during unprotected sex (sex without a condom). It can affect the vagina, vulva, cervix, or urethra.

Trichomoniasis is treated by a gynecologist, urologist, or primary care provider with the use of antibiotics that are taken by mouth. It is important that all partners are treated in order to eliminate the infection and prevent reinfection.

female provider talking to female patient at an appointment

Common symptoms

The main symptoms of trichomoniasis are:

Pain and discomfort with urination;
Foul-smelling yellow or greenish vaginal discharge;
Thin, white discharge from the penis;
Vulvovaginal (genital) redness.

Symptoms are often more intense during and right after your period due to pH changes in the vagina.

In men and people assigned male at birth (AMAB), it is common for the parasite to remain in the urethra, with the potential to cause a more serious infection, with swelling of the prostate and inflammation of the epididymis (epididymitis).

Symptoms can emerge 5 to 28 days after exposure, however in some cases the infection may be asymptomatic.

What is the smell associated with trichomoniasis?

Trichomoniasis can cause a yellow-green vaginal discharge with a fishy odor that may be thick, thin, or frothy.

What to do

It is important to consult your primary care provider, gynecologist, or urologist if you are concerned that you may have trichomoniasis. Testing can be done to confirm the infection in addition to a physical exam.

Confirming a diagnosis

The diagnosis of trichomoniasis is made by a primary care provider, gynecologist, or urologist based on symptoms and a physical exam. Your provider may also take a detailed sexual history.

Diagnosis also typically involves examining a sample of vaginal or penile discharge under a microscope to identify the protozoan. A urine test may also be ordered.

These tests are used to confirm the diagnosis so that treatment can be started as soon as possible in order to prevent complications.

Read about other types of vaginal infections.

Transmission and spread

Trichomoniasis is primarily spread through having sex without a condom with someone who has trichomoniasis.

While rare, transmission of Trichomonas vaginalis from the mother to the fetus is possible during vaginal delivery, which can result in respiratory symptoms and conjunctivitis in the newborn.

Trichomonas vaginalis is very resistant to environmental changes and is capable of surviving in the urine and on wet sponges and towels for several hours and in water for several minutes.

There is some evidence to suggest that trichomoniasis can be spread by sharing contaminated towels or sponges, however this is extremely rare.

Treatment options

Trichomoniasis should be treated by a primary care provider, gynecologist, or urologist in order to eliminate the infection, relieve symptoms, and prevent complications.

Medications that may be prescribed by your healthcare provider include:

Metronidazole (Flagyl): the usual recommended dose is 500 mg twice a day for 5 to 7 days;
Tinidazole (Tindamax): recommended when treatment with metronidazole is ineffective. The typical dose is 2 g of tinidazole taken in a single dose.

It is important to avoid drinking alcohol during treatment with these medications as this combination can cause nausea, vomiting, abdominal pain, and malaise. Alcohol can also decrease the effectiveness of the medication.

All sexual partners should be treated in order to prevent reinfection, even if they do not have any symptoms. It is also recommended to avoid having sex during treatment.

People with trichomoniasis who are pregnant should talk to their OBGYN or midwife right away to discuss the most appropriate treatment.

Home remedies

Home remedies can be used to complement treatment with antibiotics. One method involves using pau d’arco (lapacho) tea as an external wash, being sure to rinse well with water.

Pau d’arco is a medicinal plant that possesses antiviral and antibiotic properties that may help eliminate Trichomonas vaginalis.

To make this tea, add 3 Tbsp of dried pau d’arco leaves to 1 L of water and boil for about 10 minutes. Strain and let cool slightly, then use as a wash.

Be sure to talk to your healthcare provider first before using pau d’arco or any other natural remedies.

Is it curable?

Yes, trichomoniasis is curable, however it is important to complete the entire course of treatment as prescribed by your doctor or healthcare provider to ensure rapid resolution of symptoms and to confirm that all the protozoa are eliminated. This can help guarantee that there is no further risk to your health or for transmission.

Trichomoniasis that is untreated or inadequately treated increases the risk of a person acquiring other sexually transmitted infections (STIs) such as HIV, gonorrhea, and chlamydia, as well as bacterial vaginosis.

Signs of improving or worsening infection

Symptoms of trichomoniasis should begin to improve about 2 to 3 days after starting treatment. This includes relief from itching, resolution of vaginal discharge, decreased redness, and decreased urge to urinate.

Signs of a worsening infection in people who have not started treatment, or did not follow the treatment regimen correctly, include increased redness in the genital area, a foul odor, swelling, and genital sores.

Pregnant people with trichomoniasis who do not initiate or complete treatment can experience other serious complications like preterm birth or passing the infection to the baby during delivery.

Prevention methods

Trichomoniasis can be prevented through the use of barrier methods every time you have sex, whether it is vaginal, anal, or oral sex. These include external (male) or internal (female) condoms.

Condoms also help prevent other STIs like HIV, genital herpes, chlamydia, and gonorrhea