Green vaginal discharge is almost always a sign of infection. Healthy discharge ranges from clear to white or slightly yellow, so a distinctly green or greenish-yellow color, particularly when paired with a strong odor, itching, or burning, signals that something is off and needs treatment.
Most Likely Causes
Three infections account for the vast majority of green or greenish-yellow vaginal discharge: trichomoniasis, bacterial vaginosis, and, less commonly, gonorrhea or chlamydia.
Trichomoniasis is the most classic cause of green discharge. It’s a sexually transmitted infection caused by a parasite, and it produces a thin, sometimes frothy discharge that can range from clear to yellowish to green. A fishy smell is common. About 70% of people with trichomoniasis have no symptoms at all, so the infection can go undetected for weeks or longer. When symptoms do appear, they often include irritation, burning during urination, and soreness in the genital area.
Bacterial vaginosis (BV) is not sexually transmitted but results from an imbalance in the normal vaginal bacteria. It typically produces a thin, yellow-green or gray discharge with a strong fishy odor that tends to be most noticeable after sex. BV is the most common vaginal condition in women of reproductive age, and while the discharge can look similar to trichomoniasis, BV usually causes less irritation and itching.
Gonorrhea and chlamydia more commonly cause yellow discharge rather than distinctly green, but any unusual discharge that’s different from your normal pattern can point to either infection. Both are frequently asymptomatic. When symptoms do show up, they may include painful or frequent urination, bleeding between periods, and bleeding during or after sex.
Symptoms That Point to Infection
Green discharge on its own is enough to warrant testing, but certain accompanying symptoms make infection more likely:
- Fishy or foul odor, especially one that worsens after sex
- Itching or burning in or around the vagina
- Pain or burning during urination
- Pain during sex
- Redness or swelling of the vulva
- Spotting or bleeding between periods
If you notice a sudden change in the color, amount, or smell of your discharge along with any of these symptoms, that combination is a reliable signal that something needs attention.
How Testing Works
A healthcare provider can usually narrow down the cause quickly. The visit typically involves a pelvic exam and a swab of the discharge. From there, several things help identify the specific infection.
Vaginal pH is one early clue. A normal vaginal pH sits at or below 4.5. Both BV and trichomoniasis raise pH above that level, though trichomoniasis can occasionally be present even with a normal pH. A quick smell test, where the sample is mixed with a chemical solution, can also help. If the sample releases a fishy odor, that points toward BV or trichomoniasis.
For trichomoniasis specifically, microscopy (looking at the sample under a microscope) only catches about half of cases. More sensitive molecular tests exist that are far more accurate, so if your provider suspects trichomoniasis, they may send the sample to a lab for more advanced testing rather than relying on what they see in the office. Gonorrhea and chlamydia are diagnosed through similar lab-based tests, often from the same swab or a urine sample.
Treatment and What to Expect
All of the infections that cause green discharge are treatable with antibiotics, and most clear up within a week or two.
Trichomoniasis in women is treated with a week-long course of oral antibiotics taken twice daily. A topical gel version exists but doesn’t reach high enough concentrations in the areas where the parasite lives, so oral medication is the standard. Sexual partners need to be treated at the same time to prevent reinfection, and you should avoid sex until both you and your partner have completed treatment and symptoms have resolved.
BV is also treated with oral or vaginal antibiotics. It has a frustrating tendency to recur. Roughly half of women treated for BV experience a recurrence within 12 months. Using the full course of medication as prescribed reduces that risk.
Gonorrhea and chlamydia each have their own antibiotic regimens, and because the two infections frequently occur together, providers often treat for both simultaneously if either one is detected.
Why Treatment Matters
Leaving these infections untreated carries real risks beyond ongoing discomfort. Untreated trichomoniasis increases susceptibility to HIV and can cause complications during pregnancy, including preterm birth and low birth weight. Gonorrhea and chlamydia, if they spread beyond the vagina and cervix, can lead to pelvic inflammatory disease, which may cause chronic pelvic pain, scarring of the reproductive organs, and fertility problems. BV during pregnancy has also been linked to premature delivery.
The good news is that all of these conditions respond well to treatment, especially when caught early. Green discharge is your body giving you a clear signal, and acting on it promptly leads to straightforward, effective treatment in the vast majority of cases.