Trichomoniasis that goes untreated doesn’t just linger as a minor irritation. It can cause lasting damage to the reproductive system, increase vulnerability to other infections including HIV, and create serious risks during pregnancy. Because the majority of infected people have no symptoms at all, many carry the parasite for months or years without knowing it, giving these complications time to develop.
Most People Don’t Know They Have It
The biggest reason trichomoniasis goes untreated is that most people never realize they’re infected. In a study of urban young adults, 98.5% of infected men and 73.3% of infected women reported no symptoms in the three months before testing. Without routine screening, these infections persist silently.
When symptoms do appear, they typically show up within 5 to 28 days of exposure, but the infection can last far longer than that. In women, symptoms may include yellow-green discharge, vaginal itching, and pain during urination or sex. Men may notice mild urethral irritation or discharge, though this is uncommon. The absence of symptoms doesn’t mean the infection is harmless. It simply means the damage happens quietly.
Complications in Women
For women, untreated trichomoniasis poses the most wide-ranging risks. The parasite triggers chronic inflammation in the vaginal and cervical tissue, which over time can open the door to more severe problems. One study found that women colonized with chlamydia who were also infected with trichomoniasis had nearly five times the odds of developing pelvic inflammatory disease (PID) compared to those without the parasite. PID can scar the fallopian tubes and lead to chronic pelvic pain, ectopic pregnancy, or infertility.
There is also a concerning link to cervical cancer. A large meta-analysis of nearly 474,000 women found that those infected with trichomoniasis had 1.79 times higher odds of also testing positive for HPV. More strikingly, infection was associated with more than double the odds of high-grade precancerous cervical changes and over five times the odds of cervical cancer. Researchers believe the chronic inflammation caused by the parasite may help HPV gain a foothold and progress more aggressively.
Complications in Men
Men often get the impression that trichomoniasis is a “women’s infection,” but leaving it untreated carries real consequences. The parasite can travel up the urethra and reach the prostate, potentially causing prostatitis, a painful inflammation that leads to difficulty urinating, pelvic discomfort, and increased urinary frequency. It can also cause epididymitis, an inflammation of the tube that stores sperm.
Persistent infection has been linked to impaired sperm function, including reduced motility and abnormal shape, which can diminish fertility. In older men, particularly those over 55 who already have an enlarged prostate, trichomoniasis can significantly worsen urinary symptoms and make existing conditions harder to manage.
One partial silver lining for men: some studies suggest spontaneous clearance occurs in 36% to 69% of male infections without treatment. The reasons aren’t well understood, and the range is wide enough that no one should count on it. Women do not appear to clear the infection on their own at meaningful rates.
Risks During Pregnancy
Untreated trichomoniasis during pregnancy raises the stakes considerably. A systematic review and meta-analysis found three significant associations. Pregnant women with trichomoniasis had 1.27 times the odds of delivering preterm, nearly double the odds (1.87 times) of experiencing premature rupture of membranes, and more than double the odds (2.12 times) of having a low-birth-weight baby. Each of these outcomes carries its own cascade of health risks for the newborn, including respiratory problems and longer stays in neonatal intensive care.
Higher Risk of HIV and Other STIs
One of the most well-documented consequences of untreated trichomoniasis is its effect on HIV risk. The inflammation the parasite causes disrupts the protective lining of the genital tract and recruits immune cells to the area, essentially creating more entry points for HIV. A meta-analysis of 11 studies found that people with trichomoniasis were 1.5 times more likely to acquire HIV, a 50% increase in risk. In men, the infection also increases HIV shedding in seminal fluid, making transmission to partners more likely.
This increased vulnerability isn’t limited to HIV. The disrupted tissue barrier makes it easier for other sexually transmitted infections to take hold as well, creating a cycle where one untreated infection makes the next one more likely.
Treatment Is Simple and Effective
The good news is that trichomoniasis is highly curable. A seven-day course of oral antibiotics is the recommended treatment for women, with cure rates between 84% and 98%. An alternative single-dose option achieves cure rates of 92% to 100%, though multi-dose treatment cuts the chance of testing positive at a one-month follow-up by half compared to the single dose. For men, a single-dose regimen is typically effective.
Both sexual partners need to be treated at the same time, or reinfection is almost guaranteed. Retesting is recommended about three months after treatment, since reinfection rates are high.
Who Should Be Screened
Given that the vast majority of infections produce no symptoms, screening is the only reliable way to catch trichomoniasis before complications develop. The CDC recommends considering screening for women in high-prevalence settings like STI clinics and correctional facilities, as well as women with multiple sexual partners, a history of other STIs, or drug use. For women living with HIV, annual screening is recommended at minimum. There are currently no routine screening recommendations for men, which partly explains why the infection circulates so effectively.
If you’ve had unprotected sex and haven’t been tested, requesting a trichomoniasis test is straightforward. It’s not always included in standard STI panels, so you may need to ask for it specifically.