Trichomoniasis can go undetected for months or even years, because about 70% of infected people never develop symptoms at all CDC, About Trichomoniasis. There's no fixed incubation clock that forces symptoms to appear, so a silent infection can persist and keep passing between partners until a test finds it. Waiting for symptoms won't catch it. A test will.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | NAAT / lab |
| Often | no symptoms |
| If you may have it | get tested — testing, not symptoms, decides |
The essentials: why trich hides so well
Trichomoniasis is caused by Trichomonas vaginalis, a single-celled protozoan parasite that lives in the lower genital tract. It's the most common curable non-viral STI in the United States, with an estimated 2.6 million infections, and it falls disproportionately on women, who account for over 80% of diagnosed cases Sex Transm Dis, 2018.
It stays hidden because of how the parasite behaves. It can colonize the vagina or urethra and live there quietly without triggering the inflammation that produces noticeable symptoms. Roughly 7 in 10 people carry it with no clue they're infected. Men are especially likely to be asymptomatic, so a man can carry trich, feel completely fine, and reinfect a partner who has already been treated. When one partner is treated and the other still carries it, the infection lingers in couples.
There's no reliable timeline for when, or whether, symptoms will show up. Some people notice irritation within days to weeks of exposure; many never notice anything. Because the infection doesn't clear on its own, an undetected case can persist for a long stretch. If you're trying to figure out the right moment to check after a possible exposure, see our guide on when to test after exposure.
Symptoms (when they show up at all)
When trich does cause symptoms, they tend to come from inflammation of the genital tissues. The intensity ranges from mild irritation to obvious discomfort, and symptoms can come and go, which makes them easy to dismiss.
In women, common signs include itching, burning, redness, or soreness of the genitals; discomfort while urinating; and a discharge that may be clear, white, yellowish, or greenish, often with a fishy smell. That odor and discharge picture overlaps heavily with other conditions, so don't self-diagnose from symptoms alone. Here's how to tell bv discharge vs yeast infection vs trich apart.
In men, symptoms are far less common, but when present they include itching or irritation inside the penis, burning after urinating or ejaculating, and sometimes discharge. Most infected men feel nothing, and a male partner is often the silent reservoir behind a woman's repeat infections.
Testing: how trich is actually found
Because most cases are silent, a lab test is the only dependable way to know. The preferred test is a NAAT (nucleic acid amplification test, which detects the parasite's genetic material), for example the Aptima T. vaginalis assay, with a sensitivity around 95–100% CDC STI Treatment Guidelines, 2021. Suitable specimens include a vaginal swab or a female urine sample.
In practice, testing is quick: a urine cup, a self-collected swab, or a brief exam, with results usually back in a few days. You can get tested free or at low cost at health departments, Planned Parenthood, and Title X clinics. For the full rundown on sample types and accuracy, see trichomoniasis testing & diagnosis, and when you're ready you can get tested.
A common mistake is assuming a standard "STD panel" automatically includes trich. It often doesn't. If you want to be checked, ask specifically, especially as a man, since trich screening isn't routine in men and a symptomatic female partner is sometimes the only reason it's checked.
Treatment: short, effective, and finish it
Trich is cured with prescription antibiotics in the nitroimidazole class. For women, current guidelines recommend metronidazole 500 mg orally twice daily for seven days. For men, the recommended option is a single 2 g oral dose of metronidazole. Tinidazole 2 g as a single oral dose is an alternative for either.
The 2021 guidelines moved women off the old single 2 g dose after a randomized trial found that about 19% of women given the single dose were still infected at follow-up, versus about 11% on the seven-day course Muzny et al., Sex Transm Dis. The multi-day regimen roughly halved retest-positive rates, so it's now preferred for women.
| Who | Preferred regimen | Alternative |
|---|---|---|
| Women | Metronidazole 500 mg twice daily for 7 days | Tinidazole 2 g single dose |
| Men | Metronidazole 2 g single dose | Tinidazole 2 g single dose |
Two rules make or break the cure. Avoid alcohol during treatment with metronidazole or tinidazole, because the combination causes a disulfiram-like reaction (flushing, nausea, vomiting, and racing heartbeat). And all sex partners need treating at the same time, even if they feel fine, or the infection bounces back and forth. Finish every pill even once you feel better, and ask whether your partner needs treating too. Sexually active women should be retested about three months after treatment, because reinfection is common. For the full breakdown of dosing and side effects, see our page on trichomoniasis treatment.
Prevention
Correct, consistent condom use every single time lowers your risk, though it isn't a guarantee since the parasite can affect areas a condom doesn't cover. The other half of prevention is routine screening for people at risk. Trich is so often symptomless that testing catches the cases your body never warns you about. Treating partners at the same time closes the reinfection loop that keeps trich circulating.
- Use condoms consistently for vaginal sex to reduce transmission.
- Ask to be screened specifically for trich if you have symptoms, a positive partner, or risk factors.
- Make sure every current partner is treated at the same time you are.
- Plan a retest a few months after treatment if you're a sexually active woman.
When to see a clinician
Get checked if you have new genital itching, burning, abnormal discharge, or pain with urination, or if a partner tests positive even with no symptoms of your own. A diagnosis here is common and completely treatable; clinics manage it every day. The harder part is the silence. If you have a reason to test, don't wait for symptoms that may never arrive.