This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Trichomoniasis is the most common curable sexually transmitted infection, according to the CDC. It is also one of the least talked about. Many people who have it notice nothing at all.

This guide is a science-focused look at the organism behind it, what research suggests about how it behaves, how testing works, and what treatment from a clinician involves. It ends with options for getting tested in Los Angeles.

What causes trichomoniasis

Trichomoniasis is caused by Trichomonas vaginalis. The CDC describes it as a single-celled protozoan parasite. It is not a virus and it is not a bacterium.

That difference matters for care. Antibiotics for bacterial infections do not target a parasite. Trichomoniasis needs its own kind of prescription medicine, which is why a specific test is useful.

The parasite lives in the genital tract. In people with a vagina it is found in the vagina and sometimes the urethra. In people with a penis it is found in the urethra. The CDC says infection of other body sites is uncommon.

How it spreads

The CDC says trichomoniasis passes through sexual contact, including penis-in-vagina sex and vulva-to-vulva contact. Anyone who is sexually active can get it, whatever their gender or orientation.

The CDC also notes that condoms used correctly each time can lower the chance of getting or passing it. They do not remove the chance entirely.

Trichomoniasis symptoms: what research and the CDC describe

The most important fact about trichomoniasis symptoms is that they are often absent. The CDC estimates that about 70% of people with the infection have no signs or symptoms. A person can carry the parasite and pass it on without knowing.

When symptoms do appear, the CDC says they usually begin within 5 to 28 days of exposure. Some people notice them later, and some never do.

Symptoms in people with a vagina

The CDC lists these possible signs:

Itching, burning, redness or soreness of the genitals
Discomfort when urinating
A change in vaginal discharge, which can be thin or more frothy and may look clear, white, yellowish or greenish

The CDC also notes that discharge can have an unusual odor. None of these signs point to one cause alone. Bacterial vaginosis, yeast infections and other conditions can look similar, so only a test can sort them out.

Symptoms in people with a penis

The CDC says most people with a penis who have trichomoniasis have no symptoms. When symptoms occur, they can include:

Itching or irritation inside the penis
Burning after urinating or ejaculating
Discharge from the penis

Because signs are often missing, a partner's diagnosis is sometimes the first clue. If a partner tells you they were treated, ask a clinician about testing for yourself.

What research suggests about why it matters

Trichomoniasis is often mild day to day, but the CDC points to several reasons it deserves attention. These are research observations, not predictions for any one person.

Without treatment it can persist

The CDC's treatment guidelines note that untreated infection can last for months or even years. During that time the parasite can be passed to partners.

Links with HIV risk

Research summarized by the CDC suggests that trichomoniasis can make it easier to acquire HIV if exposed, and may make it easier for a person with HIV to pass it on. The inflammation the parasite causes is one proposed explanation. For this reason, the CDC 2021 guidelines recommend that women with HIV be screened for trichomoniasis at entry to care and at least once a year.

Pregnancy

The CDC says trichomoniasis in pregnancy has been associated with preterm delivery, premature rupture of membranes and low birth weight. Anyone who is pregnant and has symptoms, or whose partner was diagnosed, should tell their prenatal care provider. A clinician can decide what testing and treatment make sense.

How testing works

You cannot tell trichomoniasis from other conditions by symptoms alone. Testing is the only way to find out what is causing them, and it is the only way to learn about an infection that causes no symptoms.

NAAT: the method the CDC recommends

The CDC 2021 STI Treatment Guidelines recommend a nucleic acid amplification test, or NAAT, as a highly sensitive way to detect Trichomonas vaginalis. A NAAT looks for the parasite's genetic material in a sample.

The CDC guidelines list the sample types:

For people with a vagina: a vaginal swab, an endocervical swab or urine
For people with a penis: urine, a urethral swab or semen

Many clinics let a patient collect the vaginal swab themselves in a private room. The guidelines describe this as an acceptable way to collect the sample.

Older methods

Some clinics use a wet mount, where a sample is examined under a microscope right away. The CDC notes this approach is less sensitive than a NAAT, meaning it can miss infections that a NAAT would find. Rapid point-of-care tests also exist. If you are unsure which method a clinic uses, you can ask.

When to test after an exposure

The CDC does not publish a single window period for trichomoniasis in the way it does for some other infections. A clinician can advise on timing based on your exposure and any symptoms. If you are unsure, asking early is better than guessing.

Quality indicators to look for

A trustworthy testing experience tends to share a few traits:

The clinic can tell you which infections the visit includes, and trichomoniasis is not always part of a standard panel
You are told what kind of test is used and how long results take
A clinician is available to explain a positive result and prescribe treatment
The clinic explains how your results are kept private

That first point is worth special attention. Some clinics test for chlamydia, gonorrhea, syphilis and HIV by default. If you want trichomoniasis included, ask when you book.

Trichomoniasis treatment: what a clinician prescribes

Trichomoniasis is curable. According to the CDC, treatment is a prescription antimicrobial medicine taken by mouth. The CDC guidelines recommend a medicine from the nitroimidazole class. Which one, and for how long, is a decision for your clinician. The guidelines differ by sex and circumstance, so this page does not list doses or schedules.

Over-the-counter products for vaginal itching do not treat trichomoniasis. Treating a different condition by guesswork can delay the right care.

Safety profile and questions to ask

Like any medicine, these prescriptions have side effects and cautions. Things worth raising with the clinician or pharmacist include:

Alcohol. The CDC guidelines advise avoiding alcohol around the time of treatment with these medicines because of possible unpleasant reactions. Ask how long to wait.
Allergies. Tell the clinician about any past reaction to this class of medicine.
Pregnancy and breastfeeding. The guidelines include specific advice for both. Tell the clinician if either applies.
Other medicines. Mention everything you take, including supplements.
Common side effects. Ask what to expect, such as nausea or a metallic taste, and when to call back.

Finish the course, then retest

Take the medicine as prescribed. Stopping early because symptoms fade can leave the infection in place.

The CDC also notes that repeat infection is common after treatment. For that reason, the 2021 guidelines recommend retesting within three months for sexually active women who were treated, and say retesting can be considered for men too. Retesting is mainly about catching a new infection, often from a partner who was not treated.

Partners and avoiding reinfection

Partners are a key part of treatment. If only one person is treated, the parasite can pass back and forth.

The CDC advises that all current sex partners be evaluated and treated, and that people wait to have sex again until everyone has finished treatment and any symptoms have gone away. Tell your clinician about recent partners. They can explain how to get partners care.

In California, Health and Safety Code section 120582 allows expedited partner therapy for chlamydia, gonorrhea and other STIs determined by the state health department or recommended in current CDC guidelines, according to the CDC's page on the legal status of EPT in California. Whether it applies to trichomoniasis in your situation is a question for your clinician.

If you also want to understand another common curable infection, our guide to chlamydia symptoms, testing and treatment in Los Angeles covers it in the same plain terms.

Getting tested in Los Angeles

Los Angeles County has several free and low-cost options. We keep a running list of local testing clinics, and a fuller walkthrough in STD testing in Los Angeles: where to get tested.

Because trichomoniasis is not part of every standard panel, call ahead and ask whether it is included. Here is what the sources say about a few options.

Los Angeles County Department of Public Health sexual health clinics

The county Department of Public Health runs sexual health clinics. Its Sexual Health Clinics page says services are provided at no patient charge, and that insurance is billed if you have it, with no copay or coinsurance. DPH says its clinics are open to everyone regardless of citizenship, and that it will not report immigration status.

Central Health Center: 241 Figueroa St., Los Angeles, CA 90012. Offers STD testing, HIV testing, PrEP, PEP, doxy-PEP and treatment. Appointments are preferred, with limited walk-ins. Registration is Tuesday through Friday, and the clinic is closed Monday.
MLK Jr. Center for Public Health: 11833 S. Wilmington Ave, Los Angeles, CA 90059. Full-service, with the same services. Appointments are preferred, with limited walk-ins.
Pacoima Health Center: 13300 Van Nuys Blvd, Pacoima, CA 91331. Screening only. DPH says people with symptoms or a possible exposure should book at another DPH clinic for evaluation and treatment.

All DPH sexual health appointments go through one scheduling line, (213) 449-7009. DPH says telehealth visits are offered by phone booking, and that results come through the LA Health Portal in 2 to 10 business days. Ask the scheduler whether trichomoniasis testing is part of your visit.

Other clinics

Los Angeles LGBT Center, McDonald/Wright Building: 1625 N. Schrader Blvd., Los Angeles, CA 90028. The county lists walk-ins accepted and same-day appointments, Monday to Friday, 10am to 7pm. Phone (323) 993-2997. The Center's page does not state the cost of STI testing, so ask when you call.
AHF Wellness Center, Western: 1811 N. Western Ave., Los Angeles, CA 90027. AHF says it offers free tests for gonorrhea, chlamydia, syphilis and HIV with no appointment needed. Its FAQ does not mention trichomoniasis, so ask directly. Phone 1 (855) 783-2434.
APLA Health, Baldwin Hills: 3741 S. La Brea Ave., Los Angeles, CA 90016. APLA describes its sexual health services as free or low-cost but does not list fee details. Appointments are directed through its site. Phone (213) 201-5000.
Watts Health Center: 10300 Compton Ave., Los Angeles, CA 90002. Listed by the county for STD screening and treatment. Cost and walk-in policy are not published in the county listing, so check with the clinic. Phone 1 (323) 564-4331.
Children's Hospital Los Angeles, STD services for youth ages 12 to 24: 3250 Wilshire Blvd., 3rd Floor, Los Angeles, CA 90010. Phone 1 (323) 361-7550. Cost and walk-in policy are not listed, so check with the clinic.

Hours change, so confirm with each clinic before you go.

Teens and young adults

Under California Family Code section 6926, as amended by AB 499 in 2011, a minor who is 12 or older can consent to STI testing and treatment. Guttmacher Institute's summary lists no parental notification provision for California. DPH says patients 12 and older can be tested and treated without their parents knowing.

Finding more options

The CDC's GetTested tool at gettested.cdc.gov lets you look up testing sites by ZIP code. The county STD hotline, 800-758-0880, can also help you find free testing.

The numbers in context

The county does not publish a trichomoniasis rate on the pages we reviewed, since it is not among the infections its surveillance snapshot highlights. For perspective, the LA County Department of Public Health's 2024 STI Surveillance Snapshot reports 493 chlamydia cases per 100,000 people and 252 gonorrhea cases per 100,000 people in the county, excluding Long Beach and Pasadena. These are provisional figures. They show that sexually transmitted infections are a routine public health concern here, which is why regular conversations with a clinician are an ordinary part of care.

Key takeaways

Trichomoniasis is caused by a parasite, and the CDC calls it the most common curable STI.
The CDC estimates about 70% of people with it have no symptoms.
NAAT is the CDC-recommended way to detect it, and only a test can tell it apart from conditions with similar symptoms.
Treatment is a prescription medicine from a clinician, and partners need care too.
The CDC recommends retesting within three months for treated women because reinfection is common.
Ask any clinic whether trichomoniasis is included in the visit.

Trichomoniasis: Symptoms, Testing and Treatment in Los Angeles