Trichomoniasis causes genital itching, unusual discharge, and discomfort during urination, though many people with the infection have no symptoms at all. It’s caused by a microscopic parasite called Trichomonas vaginalis, spread through sexual contact, and it affects women and men differently.
Symptoms in Women
Women are more likely than men to develop noticeable symptoms, though even among women, only about half will have obvious signs of infection. The most common symptom is a change in vaginal discharge. The discharge can be clear, white, yellowish, or greenish, and it often has a fishy smell. It may be thinner than normal or simply increase in volume.
Beyond discharge, women commonly experience itching, burning, redness, or soreness around the genitals. Urination can become uncomfortable or painful. Sex may also hurt, a symptom known as dyspareunia. In severe acute infections, the inflammation can produce tiny hemorrhagic spots on the vaginal walls and cervix, sometimes called “strawberry cervix” because of the spotted, reddish appearance. This is relatively rare, showing up in about 2% of cases, and it’s typically only visible during a clinical exam.
Symptoms can range from barely noticeable irritation to intense discomfort that disrupts daily life. They may also come and go, which sometimes leads people to assume the problem resolved on its own.
Symptoms in Men
Men are far less likely to have symptoms. Only about 10% of infected men develop urethritis (inflammation inside the urethra) or urethral discharge. When symptoms do appear, they typically include itching or irritation inside the penis, a mild discharge, and burning after urination or ejaculation.
Because so few men show symptoms, they often unknowingly carry and transmit the parasite. The infection can persist for weeks or months without any sign of trouble, making it easy to pass to sexual partners without realizing it.
How Many People Have No Symptoms
The asymptomatic rate for trichomoniasis is strikingly high. Fewer than half of infected women develop the characteristic vaginal discharge, and the vast majority of infected men never notice anything wrong. This is one of the reasons trichomoniasis is so widespread: people who feel fine don’t seek testing, and the parasite continues to spread.
When symptoms do develop, they typically appear within 5 to 28 days after exposure, though some people remain symptom-free for much longer before signs eventually emerge. Others never develop symptoms at all but can still pass the infection to partners.
How Trichomoniasis Differs From Other Infections
The symptoms of trichomoniasis overlap with bacterial vaginosis and yeast infections, which makes it difficult to identify based on symptoms alone. A few features can help distinguish it. The greenish or yellowish tint of the discharge is more characteristic of trichomoniasis than of a yeast infection, which typically produces thick, white discharge. The fishy odor is shared with bacterial vaginosis, but the redness, soreness, and inflammation tend to be more pronounced with trichomoniasis.
In men, the symptoms can mimic chlamydia or gonorrhea, both of which also cause urethral discharge and burning during urination. The only reliable way to tell the difference is through testing.
How It’s Diagnosed
If your symptoms sound like trichomoniasis, the type of test your provider uses matters. The traditional method, examining a swab of vaginal fluid under a microscope (called a wet mount), catches only 44% to 68% of infections. Its accuracy drops further if the slide isn’t examined immediately, falling to around 20% within an hour of collection.
Newer molecular tests are far more reliable. Nucleic acid amplification tests (NAATs) detect the parasite’s genetic material and have sensitivity rates of 95% to 100%, meaning they catch nearly every infection. These tests can be run on vaginal swabs, cervical swabs, or urine samples. For men, urine-based molecular tests are the most practical option, since the traditional wet mount was designed for vaginal specimens.
If you’re experiencing symptoms and a wet mount comes back negative, it’s worth asking about a molecular test before ruling trichomoniasis out.
Risks of Untreated Infection
Trichomoniasis is curable with a short course of antibiotics, but leaving it untreated creates real risks. In pregnant women, the infection is linked to preterm birth and low birth weight. It also increases susceptibility to HIV by causing inflammation in the genital tissue, which creates more entry points for the virus. The same inflammatory damage can raise the risk of acquiring or transmitting other sexually transmitted infections.
Chronic, untreated trichomoniasis in women can lead to persistent pelvic discomfort and ongoing vaginal inflammation. In men, it can contribute to prostatitis and reduced fertility over time, though these complications are less well documented. Because treatment is straightforward and effective, there’s no reason to leave the infection to linger, especially given the risks during pregnancy and the potential to spread it to others unknowingly.