You noticed some itching, an unusual discharge, or a sting when you pee, and now you're wondering if it's an STI. It's a stressful place to be. The truth about trichomoniasis is reassuring in one way and tricky in another: it's the most common curable sexually transmitted infection in the world, but most people who have it feel completely fine.
That gap between how common it is and how silent it can be is exactly why it helps to know what the symptoms actually look like, when they tend to show up, and why a quick test (not a guess) is the only way to know for sure.
What is trichomoniasis?
Trichomoniasis (often shortened to "trich") is a sexually transmitted infection caused by a tiny parasite called Trichomonas vaginalis. It spreads through sexual contact and is the most common nonviral, curable STI worldwide. A peer-reviewed global analysis put the pooled prevalence at about 8% (with a range of roughly 1% to 35% depending on the country and population).
In the United States, the CDC estimated more than 2 million infections in 2018. Rates are higher in women than in men and tend to rise with age in women. Because so many cases cause no symptoms, the infection is widely thought to be underdiagnosed.
What are the symptoms of trichomoniasis?
Here's the part that surprises most people: about 70% of people with trichomoniasis have no signs or symptoms at all, according to the CDC. NIH/StatPearls notes the asymptomatic rate in women may be as high as 85%. So feeling fine does not rule it out.
When symptoms do appear, they differ by sex. In women, signs commonly include:
- Genital itching, burning, redness, or soreness
- Discomfort or pain when urinating
- A thin discharge that may be clear, white, yellowish, or greenish
- A discharge with an unusual or fishy odor
Trichomoniasis symptoms in men
Men are often asymptomatic, which is one reason the infection passes back and forth between partners so easily. When men do notice symptoms, they may include itching or irritation inside the penis, burning after urination or ejaculation, or some discharge.
Because symptoms in men are usually mild or absent, a male partner can carry and pass on the infection without realizing it. That's why testing and treating partners together matters so much (more on that below).
How long after exposure do symptoms appear?
When symptoms do show up, they typically emerge 5 to 28 days after infection, according to the CDC and Mayo Clinic. Some people develop them much later, and others never develop them at all.
This variable timeline is part of why trichomoniasis is hard to pin down by feel alone. You can't reliably trace it back to a single encounter, and the absence of symptoms in the first few weeks doesn't mean you're in the clear. If you've had a possible exposure, testing is far more dependable than waiting and watching.
How is trichomoniasis diagnosed and treated?
Trichomoniasis cannot be diagnosed on symptoms alone, because its signs overlap with other infections like bacterial vaginosis and other STIs. A lab test is required. A clinician typically does a quick exam and takes a sample of urine or fluid from the vagina or penis for testing.
The good news: it's curable. Standard treatment is a single oral dose of metronidazole or tinidazole. All sex partners need to be treated at the same time to prevent passing the infection back and forth (reinfection is common when only one partner is treated). Patients are generally advised to avoid alcohol for 72 hours after metronidazole or tinidazole. Always follow the specific instructions your clinician gives you—this is general education, not a prescription.
When should you see a doctor?
See a clinician if you notice unusual genital discharge, odor, itching, burning, or pain with urination—or if a partner has been diagnosed with trichomoniasis or another STI. Because the infection is so often silent, it's also reasonable to ask about STI testing as part of routine sexual-health care, even without symptoms.
Untreated trichomoniasis can cause ongoing irritation and is linked to inflammation of the lower urogenital tract. If you're pregnant and have symptoms or a possible exposure, mention it to your provider, since STIs in pregnancy deserve prompt attention. Testing is simple, treatment is usually a single dose, and getting checked is the fastest way to stop worrying and protect both you and your partners.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting any new skincare treatment, especially if you have underlying health conditions, are pregnant, or are taking medications.
