Greenish yellow vaginal discharge typically signals an infection, most commonly trichomoniasis or bacterial vaginosis. Normal discharge ranges from clear to white and doesn’t have a strong smell, so a shift toward green or yellow, especially with odor, itching, or irritation, is your body telling you something needs attention.
Why Discharge Turns Green
The green tint in discharge comes from white blood cells rushing to fight an infection. These immune cells contain an enzyme that was originally named “verdoperoxidase” because of its intense green color. It makes up as much as 5% of the dry weight of certain white blood cells and is the same substance that gives pus its greenish hue. So when you see greenish yellow discharge, you’re essentially seeing evidence of your immune system actively responding to an invader, whether that’s bacteria, a parasite, or another source of inflammation.
Trichomoniasis: The Most Common Cause
Trichomoniasis is a sexually transmitted infection caused by a tiny parasite, and it’s one of the most frequent reasons for greenish discharge. The CDC estimates there were over two million trichomoniasis infections in the United States in 2018 alone. The tricky part: about 70% of people with the infection have no symptoms at all, which means it often spreads without anyone realizing it.
When symptoms do show up, they typically include a thin discharge that can be clear, white, yellowish, or greenish, often with a fishy smell. Itching, burning, redness, and soreness around the genitals are also common. Symptoms can appear anywhere from 5 to 28 days after exposure, though some people don’t develop them for much longer.
Trichomoniasis is treated with a course of oral antibiotics. Women typically take a twice-daily regimen for seven days, while men often receive a single larger dose. Sexual partners need treatment at the same time to prevent reinfection.
Bacterial Vaginosis
Bacterial vaginosis (BV) happens when the normal balance of bacteria in the vagina shifts, allowing certain types to overgrow. The discharge is often grayish-white, but it can take on a yellowish or greenish tinge in some cases. The hallmark is a strong fishy odor, particularly after sex. Unlike trichomoniasis, BV isn’t sexually transmitted, though sexual activity can increase the risk of developing it.
A normal vaginal pH sits around 4 to 4.5. With BV, the pH rises above 4.5, and with trichomoniasis, it can climb to 5.0 or even 6.0 and higher. This shift in acidity is part of what allows the problematic organisms to thrive. BV is also treated with antibiotics, though the specific type and duration differ from trichomoniasis treatment.
Less Common Causes
Not every case of greenish yellow discharge points to an STI. A condition called desquamative inflammatory vaginitis (DIV) can produce strikingly similar symptoms: yellowish green discharge, vulvar itching and burning, redness inside the vaginal walls, and pain during sex. DIV involves chronic inflammation of the vaginal lining and isn’t caused by an infection. Diagnosing it requires ruling out bacterial, fungal, and sexually transmitted infections through lab testing first, because the symptoms overlap so heavily.
Gonorrhea and chlamydia can also cause abnormal discharge, though it’s more commonly yellowish than green. These infections sometimes produce no symptoms at all, which is why they’re worth testing for if you’re sexually active and notice any change in your discharge.
Risks During Pregnancy
Greenish or yellow discharge during pregnancy deserves prompt attention. Infections like trichomoniasis and BV carry specific risks for pregnant women, including the possibility of preterm labor and, in rare cases, infection of the amniotic sac. An increase in discharge volume is normal during pregnancy, but any shift in color toward green, gray, or yellow could indicate an infection that needs treatment before it affects the pregnancy.
How to Tell It’s Not Normal
A few specific signs distinguish an infection from routine changes in discharge:
- Color: Greenish, yellowish, or grayish discharge that’s different from your usual pattern
- Odor: A strong or fishy vaginal smell, especially one that’s new
- Texture: Thick, chunky, or noticeably thinner and more watery than usual
- Irritation: Itching, burning, redness, or soreness around the vulva or vagina
- Bleeding: Spotting or bleeding between periods or after sex
If you notice greenish yellow discharge, resist the urge to self-treat with over-the-counter yeast infection products. People frequently mistake other infections for yeast infections, and using the wrong treatment delays proper care. The causes of green-tinged discharge, particularly trichomoniasis and BV, require prescription antibiotics that target the specific organism involved. A healthcare provider can identify the cause with a simple swab test and get you on the right treatment quickly, often clearing the infection within a week.