Trichomoniasis: symptoms, treatment and how to tell your partner
Trichomoniasis is a very common sexually transmitted infection caused by a parasite. Most people have no symptoms, especially men, so it can pass from one partner to another without anyone noticing. It is cured with antibiotics, and the key is that your partner is treated at the same time.
What is trichomoniasis?
It is caused by the parasite Trichomonas vaginalis, which infects the vagina and urethra in women and the urethra in men. It is the most common curable STI in the world. Without treatment it can last for months or years, it increases the risk of getting other STIs, such as HIV, and in pregnancy it can lead to premature birth.
Trichomoniasis symptoms
Between 70% and 85% of people have no symptoms or only mild discomfort. If symptoms appear, it is usually between 5 and 28 days after infection:
- In women: yellow-green, frothy, bad-smelling discharge, itching, redness and burning in the vagina, discomfort when urinating and pain during sex.
- In men: itching or irritation inside the penis, burning when urinating or after ejaculation and, sometimes, discharge from the penis.
How is trichomoniasis spread?
It spreads mainly through vaginal sex without a condom, vulva-to-vulva contact and sharing sex toys without washing them. Infection in the mouth or anus is uncommon.
Testing and diagnosis
It is diagnosed with a sample of vaginal or urethral discharge, or with a urine test. Molecular tests (PCR) are the most reliable. If you test positive, also get tested for other STIs.
Trichomoniasis treatment
It is cured with antibiotics such as metronidazole or tinidazole: women are usually prescribed a 7-day course and for men a single dose may be enough. It is essential that your partner is treated at the same time, even without symptoms, so you do not reinfect each other.
Do not have sex until you have both finished treatment and the symptoms have gone.
How to tell your partner you have trichomoniasis
Telling them is essential: if your partner is not treated, they are very likely to reinfect you. Some tips:
- Be clear and avoid blame: trichomoniasis can go months or years without symptoms, so it does not show when or from whom it came.
- Explain that in men it almost never causes symptoms, so they do not assume they do not have it.
- Ask them to get treated at the same time as you and not to have sex until you have both finished.
- Choose the way: in person if it is your steady partner; with a casual partner, a message may be enough.
If you cannot or do not want to tell them yourself, you have two options: ask for help at your healthcare center, where in some cases the staff notify contacts for you, or send an anonymous text message or email with STI notice, without your name or number appearing.
Who should you notify?
Your current partner and the people you have had sex with in the last 3 months, as health guidelines generally recommend. All of them should be treated, even if they have no symptoms.
If you have been told you might have trichomoniasis
Make an appointment with your doctor or a sexual health clinic and explain that a partner has trichomoniasis. You will usually be treated even if you have no symptoms. Do not have sex until you have finished treatment.
How to prevent trichomoniasis
Use condoms for vaginal sex, wash sex toys or cover them with a new condom for each person, and get tested if you have new partners.
Frequently asked questions about trichomoniasis
Can I get trichomoniasis again?
Yes. Having had it does not protect you from new infections, and reinfection is common, especially if your partner has not been treated. That is why women are advised to get retested about 3 months after treatment.
Can you get trichomoniasis from towels or a swimming pool?
It is very unlikely, as it is from toilet seats. The parasite survives only a short time outside the body and is almost always passed on through sex or by sharing sex toys.
Other sexually transmitted infections
Syphilis · Gonorrhea · Genital herpes · HIV · Pubic lice (crabs) · HPV and genital warts · Chlamydia · Yeast infection (candidiasis) · Hepatitis A, B and C · Scabies · Mpox (monkeypox)
Sources: MedlinePlus: trichomoniasis; CDC: trichomoniasis treatment guidelines.Health information updated in October 2026. It does not replace advice from a healthcare professional.