Green discharge is almost always a sign of infection. Normal vaginal discharge ranges from clear to white, and normal penile discharge is minimal or clear. When discharge turns green or greenish-yellow, it typically means your body is fighting off bacteria or a parasite, and the color comes from white blood cells accumulating at the site of infection.
The Most Common Cause: Trichomoniasis
Trichomoniasis is the infection most closely linked to green discharge. It’s caused by a tiny parasite called Trichomonas vaginalis, spread through sexual contact, and it’s one of the most common curable STIs. The discharge is often thin, greenish or yellowish, and has a noticeable fishy smell. Symptoms typically appear 5 to 28 days after exposure, though many people (especially men) never develop symptoms at all.
In women, trichomoniasis can also cause itching, burning during urination, and redness or soreness around the genitals. In men, the parasite can cause irritation inside the penis, mild discharge, or a burning feeling after urination or ejaculation. It’s easily treated once diagnosed, but it won’t clear up on its own.
Other STIs That Cause Abnormal Discharge
Gonorrhea produces thick, cloudy, or sometimes bloody discharge from the penis or vagina. While it’s not always green, it can take on a yellowish-green appearance, particularly in men. Symptoms of gonorrhea tend to show up quickly, usually within 2 to 8 days of exposure. Chlamydia causes discharge too, but it’s generally milder and less likely to be distinctly green. Chlamydia symptoms take 1 to 3 weeks to appear, and the majority of people with chlamydia have no symptoms at all.
Both infections can affect the cervix in women, sometimes causing a pus-like discharge visible at the cervical opening along with bleeding between periods or after sex. In men, these infections cause urethritis, an inflammation of the urethra that produces discharge ranging from watery to thick and purulent. The color of that discharge can range from white to yellow to green depending on the severity of the infection and how long it’s been present.
Green Discharge in Men
Penile discharge that’s green, yellow, or cloudy is a strong indicator of a sexually transmitted infection. The most common culprits are gonorrhea, chlamydia, trichomoniasis, and a bacterium called Mycoplasma genitalium. Some men notice the discharge only in the morning or only when they squeeze the tip of the penis. Others have a more obvious, steady flow.
Pain or burning during urination often accompanies the discharge, but not always. Men can carry these infections with no symptoms for weeks or months, so the appearance of discharge doesn’t necessarily mean the infection is recent. Any visible discharge from the penis that isn’t pre-ejaculate or semen warrants testing.
Non-Infectious Causes
A retained foreign object in the vagina, most commonly a forgotten tampon, can produce foul-smelling discharge that may turn green or gray. The smell is often the most striking symptom, sometimes described as rotten. This happens because bacteria multiply rapidly around the object, creating an environment that mimics a serious infection. Removing the object usually resolves the discharge within a day or two, though antibiotics are sometimes needed if infection has set in.
Bacterial vaginosis, while more often associated with gray or white discharge and a fishy odor, can occasionally produce greenish discharge in more advanced cases. BV is not an STI. It results from an imbalance in the normal bacteria of the vagina, and it shifts the vaginal pH above 4.5 (normal is around 4.0 to 4.5). Trichomoniasis pushes the pH even higher, into the 5 to 6 range, which is one way clinicians distinguish between the two.
Green Discharge During Pregnancy
Discharge increases naturally during pregnancy, and most of it is harmless. But green, gray, or yellow discharge during pregnancy can signal an infection that needs prompt treatment. Untreated vaginal infections during pregnancy carry real risks, including preterm labor and, in rare cases, infection of the amniotic sac surrounding the baby.
Trichomoniasis during pregnancy has been associated with delivering early and having a lower birth weight baby. Gonorrhea and chlamydia can also cause complications during delivery if untreated. Green discharge at any stage of pregnancy is worth bringing up with your provider right away rather than waiting for your next scheduled visit.
What Green Discharge Looks Like vs. Normal
Normal vaginal discharge changes throughout the menstrual cycle. It can be clear, white, or slightly off-white. It may be thin and slippery around ovulation or thicker and stickier at other times. It generally has no strong odor. None of these variations should be green.
Green discharge specifically is often accompanied by at least one other symptom:
- A strong or fishy odor, especially after sex
- Itching or burning around the vagina or vulva
- Pain during urination
- Spotting or bleeding between periods
- Redness or swelling of the vulva or the head of the penis
That said, green discharge can appear on its own with no other symptoms. The absence of pain or odor doesn’t rule out infection.
Getting Tested and What to Expect
Testing for the infections behind green discharge is straightforward. For women, it usually involves a swab of the vaginal or cervical area, or sometimes just a urine sample. For men, a urine test is standard, and a urethral swab may be used if discharge is present. Results for gonorrhea, chlamydia, and trichomoniasis typically come back within a few days.
All three of these infections are curable with antibiotics or antiparasitic medication. Trichomoniasis and bacterial vaginosis are each treated with a single course of medication. Gonorrhea and chlamydia require their own specific treatments, and because they frequently occur together, testing for both at once is standard practice. Sexual partners need to be treated at the same time to prevent reinfection, which is one of the most common reasons these infections come back.
If you’ve noticed green discharge, don’t wait to see if it resolves. Infections that cause green discharge can spread to the uterus, fallopian tubes, or epididymis if left untreated, leading to more serious complications including fertility problems. Early testing and treatment prevent nearly all of these outcomes.