Green discharge is not normal. Healthy vaginal or penile discharge ranges from clear to white to slightly yellow, and green coloring almost always signals an infection that needs treatment. The most common culprits are sexually transmitted infections, but a few non-infectious causes can produce similar-looking discharge.
What Normal Discharge Looks Like
Vaginal discharge changes throughout the menstrual cycle, and these shifts are completely healthy. In the days after a period, discharge tends to be dry or tacky with a white or slightly yellow tint. As ovulation approaches, it becomes wetter, creamier, and eventually stretchy and slippery, resembling raw egg whites. After ovulation, it dries up again until the next period. These changes are driven by shifting levels of estrogen and progesterone.
The key features of healthy discharge: it falls somewhere on the clear-to-white-to-pale-yellow spectrum, and it’s generally odorless. Green falls outside that range. So does a strong fishy or foul smell. If your discharge has turned green or greenish-yellow, something is going on that your body can’t resolve on its own.
Trichomoniasis: The Most Common Cause
Trichomoniasis is a sexually transmitted infection caused by a parasite, and it’s one of the most frequent reasons for green or greenish-yellow discharge. The CDC describes the discharge as thin or increased in volume, ranging from clear to white, yellowish, or greenish, often with a noticeable fishy smell. Other symptoms include itching, burning, genital redness, and discomfort while urinating.
Trichomoniasis is tricky because many people, especially men, have no symptoms at all. Among women who do develop symptoms, they can appear days to weeks after exposure. The infection won’t clear up without antibiotics, and leaving it untreated increases the risk of contracting other STIs.
Gonorrhea and Chlamydia
Gonorrhea is the other major infection associated with green or yellowish-green discharge, particularly in men. Urethral discharge from gonorrhea can range from scanty and clear to thick and purulent (pus-like). It often comes with pain during urination. Chlamydia can cause similar symptoms, though the discharge tends to be lighter in color and volume.
In women, gonorrhea and chlamydia sometimes produce abnormal vaginal discharge, but they can also cause no noticeable symptoms at all while silently damaging the reproductive tract. That’s one reason green discharge warrants testing even if other symptoms are mild. Importantly, distinguishing between gonorrhea, chlamydia, and other infections based on appearance alone isn’t clinically possible. The color and consistency of discharge don’t reliably point to one cause over another, which is why lab testing matters.
Non-Infectious Causes
A retained foreign body, most commonly a forgotten tampon, can produce discharge that looks green or yellow-green and smells intensely foul. The discharge is often blood-stained and purulent, and it may come with lower abdominal pain. In case reports, retained objects have caused these symptoms for weeks or even months before the person realizes what’s happening. Removing the object typically resolves the discharge, though antibiotics are sometimes needed if the surrounding tissue has become infected.
Bacterial vaginosis, while more commonly linked to grayish-white discharge, can occasionally produce a greenish tint. The hallmark of BV is a strong fishy odor, especially after sex. It’s not an STI but rather an overgrowth of certain bacteria that normally live in the vagina.
How the Cause Gets Identified
A healthcare provider will typically start with a swab of the discharge. The traditional approach is examining the sample under a microscope (called a wet mount), but this method misses a significant number of infections. Microscopy catches only about 49% of yeast infections and 75% of trichomoniasis cases.
More advanced molecular testing is far more accurate. These tests detect the genetic material of specific organisms and catch trichomoniasis in virtually 100% of cases. They’re also the gold standard for identifying gonorrhea and chlamydia. If an initial microscopy test comes back negative but you still have symptoms, molecular testing or a culture should be the next step.
What Treatment Looks Like
All of the major infectious causes of green discharge are treatable with antibiotics. Trichomoniasis and gonorrhea each require specific antibiotic regimens, and treatment is usually a short course, sometimes a single dose. Sexual partners need to be treated at the same time to prevent reinfection.
You should expect the discharge to start improving within a few days of beginning treatment, though it can take a week or so for things to fully return to normal. Avoid sexual contact until treatment is complete and symptoms have resolved. If your discharge hasn’t improved after finishing the prescribed course, follow up for retesting, as reinfection or antibiotic resistance could be the issue.
Green Discharge in Men
Men don’t produce the same kind of baseline discharge that women do, so any visible discharge from the penis is worth investigating. Green or yellowish discharge from the urethra is most commonly caused by gonorrhea, chlamydia, or trichomoniasis. It may appear alongside pain during urination or itching at the tip of the urethra, though some men notice discharge as their only symptom.
The same molecular tests used for women are the gold standard for men. Gram staining of the discharge under a microscope can sometimes provide a quick presumptive diagnosis of gonorrhea when performed by someone experienced, but confirming the specific infection still requires lab testing.