What Is Bacterial Vaginosis?

This informational guide, part of POPSUGAR's Condition Center, lays out the realities of this health concern: what it is, what it can look like, and strategies that medical experts say are proven to help. You should always consult your doctor regarding matters pertaining to your health and before starting any course of medical treatment.

Every year, one in three people with vaginas will get bacterial vaginosis (BV), a type of bacteria overgrowth that results from an imbalance in vaginal pH. The condition can bring on symptoms of pain, itching, and abnormal discharge — and if it's not treated correctly, it can keep coming back. And yet, misdiagnosis is frustratingly common, with BV often being confused for yeast infections or UTIs. That's why it's so important to know what BV is, what it isn't, and how to treat it.

Bacterial vaginosis (BV) is a common vaginal infection caused by the overgrowth of disruptive bacteria in the vaginal microbiome. "This is in contrast to an optimal vaginal microbiome, which is often dominated by protective bacteria like Lactobacillus, a type of lactic-acid-producing bacteria that fights pathogens and keeps infections away," says Krystal Thomas-White, PhD, a senior scientist at Evvy. This shift in normal bacteria flora can present with an increase in vaginal discharge (often gray, white, or green), a vaginal odor that's typically described as "fishy," vaginal itching, or burning during urination. Bacterial vaginosis can also be asymptomatic.

According to the Centers for Disease Control and Prevention (CDC), BV is the most common vaginal condition in women ages 15 to 44, and it disproportionately affects Black and Hispanic women. Almost 30 percent of people with vaginas get BV each year, per the CDC.

However, even though bacterial vaginosis is the most common vaginal infection, it is often misdiagnosed. "Our clinical definition of BV has not evolved since we invented technology that allows us to look at the microbiome," says Dr. Thomas-White, whose hope is that an expanded definition will include more detailed traits in order to more accurately identify it. "Improving our characterization of infections like bacterial vaginosis and its associated outcomes will help us take a more proactive approach to vaginal health, while also improving diagnostics and treatment options."

BV is caused by an overgrowth of disruptive microbes in the vagina (which research has shown is associated with sexual activity), hormonal fluctuations, smoking, douching, and more, Dr. Thomas-White says. "That said, there are still critical research gaps that need to be addressed in our understanding of what can cause BV and how it manifests, given that it is a complex condition with overly simplistic definitions and treatments."

BV is often treated with antibiotics prescribed by a doctor. Commonly used antibiotics include clindamycin or metronidazole, which may be prescribed for five to seven days. Both are available intravaginally and orally. However, creams are recommended, because oral treatments tend to cause more side effects, according to the Mayo Clinic.

While antibiotics clear up to 85 percent of bacterial vaginosis cases within a month, for over half of these patients, the infection will return within six months. This is because whatever first triggered the vaginal microbiome imbalance in the first place is often still present. It may be necessary to return to your doctor for evaluation if symptoms reoccur. Your healthcare provider may suggest extended-use metronidazole therapy or lactobacillus colonization therapy to boost your vaginal microbiome.

To help prevent bacterial vaginosis, the Mayo Clinic recommends using mild, nondeodorant soaps and unscented tampons or pads and avoiding douching.