Trichomoniasis is an infectious disease caused by the parasite Trichomonas vaginalis (Wikipedia). It is a common sexually transmitted infection, and the practical answer to your question is short: it spreads through sexual contact, a swab or urine sample at a sexual health clinic confirms it, and it is treatable with antibiotics. The rest of this page fills in the specifics so you can act on that answer without looking anything up.
What trichomoniasis is and how it spreads
Trichomoniasis — often shortened to “trich” — is an infection caused by a parasite, Trichomonas vaginalis (Wikipedia). That single sentence is the core definition: it is a parasite-driven infection, not a virus or a bacterium, and it is passed between sexual partners. Because it is a sexually transmitted infection, the people at risk are anyone who is sexually active, and the risk rises with new or multiple partners and with sex without a barrier.
The route of transmission is sexual contact. The parasite lives in the genital tract, and it passes from one person to another during sex. That is the condition that changes your answer: if you are sexually active, you are in the group for whom testing is relevant, and if you have a new partner or more than one partner, that relevance increases. The practical consequence is that a test is the only way to know your status, because the infection does not announce itself reliably. Which is the next thing to understand.
Symptoms: what to look for, and why silence matters
The main symptoms of trichomoniasis are a yellow-green discharge from your vagina that may smell like fish, and pain when peeing (NHS). Symptoms can start 5 to 28 days after being infected, but sometimes you may not get them until much later (NHS). Symptoms can include itching in the genital area, a bad-smelling thin vaginal discharge, burning with urination, and pain with sex (Wikipedia).
The condition that changes the answer here is that many people get no symptoms at all. It’s important to get tested if you think you might have trichomoniasis (NHS). About 70% of affected people do not have symptoms when infected (Wikipedia). That means waiting for symptoms is not a reliable strategy: if you have had unprotected sex or a new partner, the absence of symptoms tells you nothing. Trichomoniasis can cause symptoms in men as well as in people with a vagina (NHS), so the silent-carrier picture applies across the board. If you notice any of the symptoms above, or if you have no symptoms but a reason to check, the next step is the test.
The test that confirms trichomoniasis
A doctor or nurse will ask about your symptoms and sexual partners, and testing is done at a sexual health clinic (NHS). The test confirms the infection by looking for the parasite, and it is the step that turns a suspicion into a diagnosis. You do not need to wait for symptoms to book it. The clinic route is the same whether you have discharge, pain, or nothing at all.
The condition that changes your answer is where you go and what to expect. A sexual health clinic is the setting the NHS describes for this assessment (NHS), and the appointment begins with a conversation about symptoms and partners before any sample is taken. If you have symptoms, say so. If you have none but a reason to test, say that too, because the clinic’s job is to work out whether testing is warranted. The stop boundary is simple: a test is what confirms trichomoniasis, and self-diagnosis from symptoms alone is not reliable given how often the infection is silent.
Treatment: it is treatable
Trichomoniasis is treatable. The infection is caused by a parasite, and the clinical route is assessment and treatment through a sexual health clinic (NHS). The practical answer is that a confirmed diagnosis leads to treatment rather than to a wait-and-see approach, and the clinic is where that treatment is arranged.
The condition that changes your answer is that treatment is not something to improvise. Because the cause is a parasite, the treatment decision belongs with the clinician who confirmed the test, and the appointment covers both the diagnosis and the plan. One further detail matters for how seriously to take it: having trichomoniasis increases the risk of getting HIV/AIDS (Wikipedia). That is a reason to get tested and treated promptly rather than to let a silent infection run its course. The stop boundary is that treatment is a clinical decision made after a confirmed test, not a guess based on symptoms.
Prevention: barrier and testing steps that reduce risk
Prevention comes down to reducing exposure during sex and checking your status when exposure may have happened. Because trichomoniasis spreads through sexual contact, using a barrier method during sex reduces the chance of passing the parasite between partners, and testing after a new partner or unprotected sex catches an infection that may be silent. The two steps work together: the barrier lowers the chance of transmission, and the test catches what the barrier did not prevent.
The condition that changes your answer is that neither step is a guarantee on its own. A barrier reduces risk but does not eliminate it, and a negative test reflects the point in time it was taken. A new exposure means a new reason to test. The practical sequence below puts the steps in order so you can act on them.
- Use a barrier method during sex to reduce the chance of passing the parasite between partners.
- Book an appointment at a sexual health clinic if you have a new partner, unprotected sex, or any symptom.
- At the appointment, tell the doctor or nurse about your symptoms and sexual partners so the assessment is accurate.
- Get tested even if you have no symptoms, because many people with trichomoniasis have none.
- If the test confirms trichomoniasis, follow the clinic’s treatment plan and ask about testing partners.
Trichomoniasis is treatable, but a silent infection still carries risk — having trichomoniasis increases the risk of getting HIV/AIDS (Wikipedia). If you have had unprotected sex or a new partner, get tested at a sexual health clinic rather than waiting for symptoms.
Where this leaves you
The direct answer to your question: trichomoniasis spreads through sexual contact, a test at a sexual health clinic confirms it, and it is treatable. If you have symptoms — yellow-green discharge, fish-like smell, pain when peeing, itching, or pain with sex — book the clinic. If you have no symptoms but a new partner or unprotected sex, book the clinic anyway, because most people with the infection have none. The stop boundary is that a test is what confirms trichomoniasis, and treatment follows a confirmed diagnosis through the clinic that tested you.