Greyish vaginal discharge typically indicates bacterial vaginosis, but it can have other causes, including some sexually-transmitted infections and other health conditions.

Vaginal discharge is a normal part of your body’s functioning. By releasing fluid, the vagina can maintain its pH balance and eliminate potentially infectious bacteria, viruses, and fungi.

It typically ranges in color from clear to white. But when it takes on an unusual color, like green or grey, it’s usually your body’s way of telling you that there may be a problem.

Bacterial vaginosis (BV) happens when there’s an overgrowth of bacteria in your vagina. Your vagina naturally contains bacteria, but sometimes harmful bacteria can overpower beneficial bacteria, resulting in BV.

One of the hallmark symptoms of BV is grey discharge. The unusual color is due to a collection of bacteria, white blood cells, and cellular waste products.

Other symptoms of BV include:

Keep in mind that BV symptoms can appear very similar to those of a yeast infection. However, the discharge caused by a yeast infection tends to be lumpy and white.

BV requires treatment with prescription antibiotics. Left untreated, it can increase your risk of certain sexually transmitted infections (STIs), so it’s important to see your healthcare provider if you have symptoms of BV.

While BV is the most likely cause of grey discharge, other things can cause it as well.

Trichomoniasis

Trichomoniasis is an STI caused by the parasite Trichomonas vaginalis. One of its most noticeable symptoms is unusually colored discharge.

In some cases it appears grey, but it can also have more of a yellow or green tint.

Other symptoms of trichomoniasis include:

  • a burning sensation in the vaginal area
  • irritation
  • pain when urinating
  • redness
  • vulvar swelling

Trichomoniasis usually responds well to a single dose of antibiotics.

You can transmit the infection to sexual partners, so it’s important to get tested as soon as you notice symptoms. Be sure to inform your recent sexual partners so they can get tested, too.

Chlamydia

Chlamydia is an STI that can cause green or grey vaginal discharge, though it doesn’t always cause symptoms.

When symptoms occur, they can include:

  • painful urination
  • rectal bleeding or unusual discharge
  • unexplained vaginal bleeding

Chlamydia requires antibiotic treatment. And as with trichomoniasis, be sure to tell any recent sexual partners about your diagnosis so they can get tested.

Gonorrhea

Gonorrhea is an STI that often doesn’t cause symptoms, making it particularly easy to unknowingly transmit to a partner. But some people might notice yellow-green discharge that appears grey to some.

Additional symptoms can include:

  • frequent urination
  • painful urination
  • rectal bleeding
  • vaginal bleeding

As with other STIs, gonorrhea requires antibiotic treatment.

Vaginal cancer

In rare cases, grey discharge may be symptom of vaginal cancer. Cancer-related discharge may also look blood-tinged or brown and be heavier than usual.

Other symptoms associated with vaginal cancer include:

Vaginal cancer is easier to treat in its early stages, so it’s best to see your healthcare provider right away if you think you have symptoms of vaginal cancer.

Vaginal discharge is completely normal, but it’s unusual for it to be grey.

In most cases, it’s a sign of either BV or an underlying infection. Both of these require prescription antibiotics, so it’s best to see your healthcare provider regardless of your other symptoms.

During your appointment, be sure to tell them when your symptoms began, any recent changes in your sexual activity, and whether anything makes your symptoms better or worse.

Grey discharge is usually a sign of some kind of infection. Left untreated, these can lead to more serious issues, including pelvic inflammatory disease.

With appropriate treatment, you should make a full recovery within a week of starting antibiotics.