Trichomoniasis (often just called “trich”) is a sexually transmitted infection caused by a parasite called Trichomonas vaginalis. It’s one of the most common curable STIs, yet many people have never heard of it.
Trich spreads through vaginal, oral, or anal sex — and most people don’t have any symptoms. When symptoms do appear, they can include unusual discharge, itching, and discomfort during urination or sex.
Trich affects people of all genders, but it’s more commonly diagnosed in people with vaginas. It’s easily treatable with antibiotics, but if left untreated, it can cause complications like inflammation, increased HIV risk, or complications in pregnancy.
How common is trichomoniasis?
Very. According to the CDC, about 2 million people in the U.S. have trichomoniasis, and many more go undiagnosed. It’s most common in people aged 14–49 and disproportionately affects Black women.
What Are Symptoms of Trichomoniasis?
Trichomoniasis often flies under the radar. Most people who have it don’t experience any obvious symptoms — or they confuse them with something else, like a yeast infection, UTI, or irritation. When symptoms do show up, they can vary depending on your body and where the infection occurs.
Symptoms in people with female biology
Trich can lead to a noticeable change in vaginal discharge. Some describe it as frothy, yellow-green, or having a strong, fishy odor. There might be itching, burning during urination, or discomfort during sex. The vulva or vagina might appear red or swollen.
Symptoms in people with male biology
People with penises often have no symptoms at all. But when they do, it might include a slight discharge from the penis, a burning sensation after peeing or ejaculation, or itching inside the penis. These symptoms are easy to miss — or dismiss.
Symptoms in anyone
Anyone can have trichomoniasis in the urethra or rectum, though these cases often go unnoticed. Oral infections are rare and usually asymptomatic.
How long can you have trichomoniasis without knowing?
It’s also possible to carry trich for months or even years without realizing it. That’s why testing matters — especially if you’ve had a new partner or multiple partners. There’s no way to visually confirm if someone has trich. It’s invisible from the outside. The only way to know for sure is to get tested. The only way to know for sure is to get tested.
What Does Trichomoniasis Look Like?
Trich usually doesn’t cause visible sores or lesions — but it can cause changes in discharge, irritation, and redness.
People with vaginas may notice:
- Yellow-green or frothy discharge
- A strong, sometimes “fishy” odor
- Swollen or red vulvar tissue
People with penises may have little to no visible signs. Some may have a thin discharge or redness at the urethra.
If you notice any changes in discharge, odor, or genital irritation, it’s worth getting tested — even if symptoms come and go.
How Is Trichomoniasis Transmitted?
Trichomoniasis is passed during sex through the exchange of genital fluids. It mostly affects the genitals, but it can also infect the urethra and — rarely — the rectum or mouth.
You can get trich from:
- Vaginal sex (most common route)
- Genital-to-genital contact
- Sharing sex toys without cleaning or using a new condom
Can trich be spread without penetration?
Yes. Skin-to-skin genital contact can be enough, even without penetration or ejaculation.
Is trich spread through toilet seats or towels?
No. Trichomoniasis can’t survive on surfaces like toilet seats, hot tubs, or shared towels.
How to prevent trichomoniasis:
- Use condoms or dental dams during all types of sex
- Get tested regularly
- Make sure your partner gets treated if you test positive
- Don’t share sex toys unless they’re cleaned or covered with a fresh condom
How Do You Test for Trichomoniasis?
Testing for trichomoniasis is easy and available in most STI panels — but not all providers include it unless you ask.
How is trich diagnosed?
- Vaginal swab or urine sample (for people with vaginas)
- Urine test (for people with penises)
- Lab-based NAAT (nucleic acid amplification test) is the most accurate
Who should get tested?
- People with symptoms (discharge, odor, irritation)
- Anyone with new or multiple partners
- Those whose partner tested positive
- People living with HIV or who are pregnant (trich increases risk of complications)
Are home tests for trichomoniasis available?
Yes. Some STI home test kits include trich — usually through vaginal swabs or urine samples. These are sent to a lab and results are provided confidentially.
How Is Trichomoniasis Treated?
Trichomoniasis is curable with antibiotics. The most common treatments are:
- A single dose of metronidazole (Flagyl) or tinidazole
- In some cases, a 7-day course may be recommended
Avoid alcohol for at least 24–72 hours after treatment, depending on the medication — it can cause severe nausea when mixed with these antibiotics.
When is it safe to have sex again?
Wait 7 days after treatment and until your partner has been treated. Otherwise, you risk passing the infection back and forth.
Complications of Trichomoniasis
If untreated, trich can lead to complications like:
- Vaginal or urethral inflammation
- Increased risk of contracting or transmitting HIV
- Pregnancy complications: preterm birth or low birth weight
- Prostate or epididymis infections (rare in men)
Even though trich is curable, not treating it increases your health risks — and your partner’s.
Outlook & Prognosis
Trich is very treatable — and most people recover fully after a single round of antibiotics. But reinfection is common, especially if a partner wasn’t treated.
There’s no natural immunity. You can get trich again — even right after treatment.
Protect yourself by:
- Following through on treatment
- Waiting a week before having sex again
- Getting your partner(s) treated too
- Retesting if symptoms return
Living With Trichomoniasis
The stigma around STIs can make a trich diagnosis feel bigger than it is. But the truth is: trich is one of the most common and most curable STIs.
Many people never have symptoms. Others get treated and move on. What matters most is getting tested, treated, and being honest with your partner(s).
If trich keeps coming back:
- Make sure all partners were treated
- Ask about the longer treatment option
- Consider retesting in 3 months
STI testing is a normal part of caring for your health — not something to feel ashamed about.
How to Tell Your Partner(s) You Have Trichomoniasis
You don’t need a perfect script — just a calm, clear approach. Honesty is the first step toward protecting each other.
Try saying:
“I tested positive for trichomoniasis. It’s really common and easy to treat with antibiotics. You should get tested too so we don’t pass it back and forth.”
Reassure them:
- It’s curable — usually with one dose
- It often has no symptoms — so they may not know they have it
- You’re not blaming them — you’re protecting both of your health
It’s a short, honest conversation — and it can prevent a long cycle of reinfection.
Last reviewed: May 2025
This content is regularly reviewed and updated to reflect the latest medical guidelines.
- Caused by: Parasite (Trichomonas vaginalis)
- Spread through: Vaginal, oral, or anal sex; genital contact; shared sex toys
- Symptoms: Often none; may include discharge, itching, odor, burning during urination or sex
- Testing: Vaginal swab or urine test; NAAT test is most accurate
- Treatment: Curable with oral antibiotics (metronidazole or tinidazole)
- Risk if untreated: Vaginal inflammation, pregnancy complications, HIV risk, reinfection
- How common: ~2 million cases in the U.S.; many go undiagnosed (CDC)