When you hear about sexually transmitted infections, you might think of chlamydia, gonorrhea, or HIV—but trichomoniasis, a parasitic infection caused by the protozoan Trichomonas vaginalis. It's one of the most common curable STIs worldwide, yet many people don’t even know they have it. Unlike bacterial STIs, trichomoniasis is caused by a single-celled organism that thrives in warm, moist areas of the body—usually the vagina, urethra, or penis. It spreads through sexual contact, and it doesn’t always cause symptoms, which is why it often goes undetected for months—or even years.
People with trichomoniasis might notice itching, burning, or discomfort during urination or sex. Women may experience a foul-smelling, yellow-green vaginal discharge. Men rarely show signs, but they can still pass it on. Trichomonas vaginalis, the parasite responsible for the infection doesn’t live long outside the body, so you can’t catch it from toilet seats, towels, or swimming pools. It’s strictly sexual. And because it often has no symptoms, testing is the only way to know for sure. The CDC estimates over 3.7 million people in the U.S. have it at any given time, but most never get diagnosed.
STI treatment, typically involving a single dose of metronidazole or tinidazole is highly effective. Both partners need to be treated at the same time, or reinfection is almost guaranteed. Avoid sex until treatment is complete and symptoms are gone. Skipping treatment doesn’t just put you at risk—it increases the chance of passing it to others, and it can raise your risk of contracting HIV if exposed. Pregnant women with trichomoniasis are more likely to deliver early or have low-birth-weight babies, so testing during pregnancy is critical.
What’s surprising is how often trichomoniasis is missed in routine screenings. Many clinics test for chlamydia and gonorrhea but skip trichomoniasis unless symptoms are obvious. If you’ve had unprotected sex, even once, and are experiencing unusual discharge, odor, or irritation, ask for a test. It’s simple: a swab or urine sample can confirm it. And unlike some STIs, it’s completely curable with the right medication.
The posts below cover real-world stories, treatment tips, and common mistakes people make when dealing with trichomoniasis and other STIs. You’ll find advice on how to talk to partners, what to expect during treatment, and why ignoring symptoms can have real consequences. Whether you’re worried about a recent encounter or just want to understand your body better, these guides give you the facts without the stigma.
