Bacterial vaginosis (BV) is caused by an imbalance of the bacteria in the vagina. The reason for this shift is not well understood, but it’s likely related to changes in the vaginal environment. For instance, you’re more prone to getting BV if you don’t change into clean clothes after a workout or if you douche. The most common bacterial overgrowth is Gardnerella vaginalis.

For some people, BV doesn’t always result in symptoms. For those who do experience symptoms, they can include a strong odor (usually described as “fishy”), a thin white or gray discharge, and vaginal irritation or discomfort.

According to the Centers for Disease Control and Prevention (CDC), BV is the most common vaginal infection in women between the ages of 15 and 44.

BV is not a sexually transmitted disease. However, if you’re sexually active, you’re at an increased risk to develop BV. Having BV can also increase the risk of getting other sexually transmitted infections.

Aside from having some uncomfortable symptoms, BV doesn’t usually cause any serious health problems for most healthy people.

Some people who get BV might need more attention. If you’re pregnant, having BV can increase the risk of preterm birth. Or, if you’re planning to undergo a gynecologic procedure, having an active episode of BV can increase your risk of infection. For these types of people, it’s important to let your doctor know if you’re experiencing symptoms so you can get treated.

BV can clear up on its own. However, if you’re experiencing any symptoms, contact your doctor to get tested and treated. This is especially true if you’re pregnant. Having BV can increase your risk of having a preterm birth.

It’s common for BV to come back. Some people are more prone to getting BV, which is likely related to their body chemistry and vaginal environment. BV may clear up and come back, or it could be that it never completely cleared in the first place.

Talk to your doctor about some lifestyle changes you can make or if you’re a candidate for medication to prevent BV.

There’s a diverse population of microorganisms in the vagina. This is normal. An overgrowth causes BV, most commonly of Gardnerella vaginalis just one kind of bacteria normally found in the vagina.

An overabundance of yeast species causes a yeast infection. Symptoms commonly include a thick, white vaginal discharge, or itching. It’s not associated with an odor.

Sometimes it can be hard to tell whether you have BV or a yeast infection based on symptoms alone. If you’re not sure, make an appointment with your doctor.

If you live in the United States, BV is usually treated with antibiotics that require a prescription. The common antibiotics are metronidazole or clindamycin. There are others that are less commonly used. In the United Kingdom, there are some non-prescription gels and creams available over-the-counter (OTC) to treat BV.

There’s medication in the form of an oral pill, a gel, or a suppository to be placed in the vagina. You shouldn’t consume any alcoholic beverages while taking metronidazole, and for 24 hours after the last dose. Doing so can cause you to have an adverse reaction to the medication.

Since the exact cause of BV isn’t well understood, it’s hard to pinpoint how to prevent it. However, reducing your number of sexual partners or using a condom for penetrative intercourse can lower your risk.

You should also avoid douching since it can wipe out the bacteria that help keep the balance in the vagina. Along these lines, it’s helpful to maintain a healthy vaginal environment.

You should see a doctor if:

  • you have any fevers, chills, or severe pain along with unusual vaginal discharge and odor
  • you have a new partner and are worried you may have a sexually transmitted infection
  • you’re pregnant and have an unusual vaginal discharge

Carolyn Kay, MD, is an obstetrics and gynecology surgeon whose special interests include reproductive health, contraception, and medical education. Dr. Kay earned her Doctor of Medicine from the State University of New York. She completed her residency at Hofstra Northwell School of Medicine in New Hyde Park.