What Is Bacterial Vaginosis (BV)?

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in the U.S. among women ages 15 to 44 years old. BV is an infection that can happen when there’s an overgrowth of the bacteria that’s normally found in the vagina. 

Some people with BV don’t have any symptoms, but others get a range of bothersome symptoms. BV is not a sexually transmitted infection (STI), but it can make you more likely to get STIs. Let’s take a closer look at BV’s signs and symptoms, causes, and treatment. 

Bacterial vaginosis symptoms 

Bacterial vaginosis symptoms can vary. More than half of people won’t know that they have it, while others can have various symptoms. If you have a BV infection, you may experience:

• A white or gray vaginal discharge, sometimes described as watery or foamy

• Vaginal irritation, including pain, itching, or burning

• Discomfort when urinating

• A foul smell, sometimes described as a fish-like odor, especially after sex 

Vaginal bleeding is not typically a symptom of BV. If you notice vaginal bleeding and a discharge, most likely there’s another explanation for your symptoms. 

What causes bacterial vaginosis?

Bacterial vaginosis is caused by an imbalance in the vagina’s natural bacteria (vaginal flora). The most common vaginal bacteria are lactobacilli, which are “good” bacteria. There are also “bad” bacteria in the vagina called anaerobes, though not as many 

The larger number of lactobacilli keeps the vaginal environment acidic by producing lactic acid. When the levels of “good” bacteria and “bad” bacteria get off balance, the vagina becomes less acidic and the anaerobes start to thrive. When anaerobes outnumber the lactobacilli, BV symptoms can develop. 

What are the risk factors for getting bacterial vaginosis?

Any person with a vagina can get BV, but not everyone gets it. Studies show that some people are more likely to get BV. This includes people who:

• Are sexually active, including those who have multiple partners or a new partner 

• Have sex without a condom

• Have an intrauterine device (IUD) in place

• Smoke cigarettes

• Regularly douche or use scented soaps and baths

• Are pregnant

Some studies show that not all people have the same vaginal flora, which may also affect a person’s risk for BV. For example, African American women are roughly twice as likely to get BV compared to non-Hispanic white women. 

Is bacterial vaginosis contagious?

Experts do not entirely understand how BV spreads. There’s some evidence that it may pass from person to person after sexual contact or from sex toys that someone with BV has touched. Scientists are still trying to understand exactly how sexual activity increases your risk of BV. It’s not clear if it’s directly passed from partner to partner. 

But there’s no indication that BV spreads from close contact outside of sexual contact. This means that BV is not passed from sharing toilet seats or bedding. 

Is bacterial vaginosis a sexually transmitted infection (STI)? 

The short answer is “no.” Bacterial vaginosis has not been classified as a STI, but this may be changing. There’s evidence that female partners can be at higher risk and should get tested if their partner is diagnosed with BV. 

Can you have sex with bacterial vaginosis?

Experts are still researching how sexual activity affects BV infection. So it’s probably best to wait to have sex until after you’ve completed BV treatment. While it’s not clear if you would spread BV to your partner, you’re at higher risk of getting other infections through sex when you have BV. 

Can men get bacterial vaginosis?

Men can’t get bacterial vaginosis. But there’s increasing evidence that men can carry the bacteria that causes the infection on their penis. Experts are still trying to understand if men can spread the infection to new female sex partners or cause a recurrent infection. 

Currently, male sex partners of women with BV do not have to be treated. But research is ongoing.

Bacterial vaginosis vs. yeast infection: What’s the difference?

Bacterial vaginosis and yeast infections can sometimes feel the same, but they’re different infections. Although you can have both infections at the same time.

Here’s a quick way to know the difference between bacterial vaginosis versus yeast infection. 

Bacterial vaginosis treatment 

The first step to treating bacterial vaginosis is confirming the diagnosis. You’ll need an in-person visit with a healthcare provider if you think you have BV. Your provider will do a physical exam and collect a small sample of your vaginal discharge for testing. 

Anyone who tests positive for BV (whether or not you have symptoms) should be treated — including pregnant women. 

Bacterial vaginosis medication 

Bacterial vaginosis is treated with antibiotics. Common antibiotic treatments for BV include:

• Metronidazole (pills or vaginal gel) 

• Clindamycin vaginal cream 

Sometimes people need more than one course of treatment to get rid of their symptoms. And about half of people with BV get it again within 12 months. So make sure to complete your full course of prescribed antibiotics and treatment, even if your symptoms improve.

Can bacterial vaginosis go away on its own? 

Sometimes people with bacterial vaginosis do get better on their own. But the longer symptoms are left untreated, the harder they can be to cure. 

Untreated BV can lead to serious complications, such as: 

• A  higher risk of getting other STDs, including HIV, from an infected partner

• A higher risk of passing HIV to a sexual partner if you are HIV positive

• A higher risk of early labor, early delivery, and low infant birth weight with pregnancy

• A higher risk of pelvic inflammatory disease (PID)

And untreated BV can increase the risk of infection after gynecological surgery. So women are often tested before surgery and treated if they test positive for the infection. 

How to prevent bacterial vaginosis 

There are a few things that you can do to lower your risk of getting BV:

• If you have sex, limit the number of partners and use a condom or dental dam.

• Do not douche or use scented soaps and baths.

• Wipe yourself front to back.

• Wash and keep clean any sexual props and toys.

• Quickly change out of wet clothes, such as bathing suits. 

• Wear cotton underwear that does not trap moisture.

But even if you try your best to prevent BV, sometimes it just sticks around. Try not to get discouraged, and talk with your healthcare provider. You may need another course of antibiotics to treat it.

Why trust our experts?

Written by:

Rebecca Horn, MD, MPH

Dr. Horn is a physician and public health specialist, with experience on four continents. She specializes in anesthesia and critical care and has a particular interest in perioperative care, as well as obstetric anesthesia.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

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