Bacterial Vaginosis (BV)

Reviewed on 7/2/2021

Facts about and Definition of Bacterial Vaginosis

Bacterial vaginosis treatment is generally with antibiotics.
Bacterial vaginosis treatment is generally with antibiotics.
  • Bacterial vaginosis is also known as nonspecific vaginitis. It results from an imbalance or overgrowth of bacteria normally present in the vagina, in contrast to an infection with foreign bacteria.
  • Gardnerella are one type of bacteria that have been implicated in the development of bacterial vaginosis.
  • Symptoms of bacterial vaginosis include vaginal discharge and odor.
  • Antibiotics, either taken orally or applied to the vagina, are the treatment of choice for bacterial vaginosis.
  • Having multiple sex partners is a risk factor for developing bacterial vaginosis, although it is not considered to be a sexually transmitted disease since it does occur in celibate women.
  • There are no effective home remedies to treat bacterial vaginosis, but the condition sometimes goes away on its own.

What Is Bacterial Vaginosis?

Bacterial vaginosis is a vaginal condition that results from an overgrowth of normal bacteria in the vagina. The condition was formerly referred to as Gardnerella vaginitis, after the bacteria that were believed to cause the condition. However, since there are a number of species of bacteria that naturally live in the vagina and can grow to excess or imbalance to cause the condition, the name bacterial vaginosis is the preferred term. As a result of overgrowth of certain bacteria, a vaginal discharge may result.

What Causes Bacterial Vaginosis?

The reasons for overgrowth of certain types of bacteria in the vagina or an imbalance in the growth of these bacteria are not fully understood. However, certain factors can increase a woman's risk of developing bacterial vaginosis, including:

  • having multiple sex partners,
  • having a female sex partner, and
  • tobacco smoking.

Vaginal douching also may increase the risk of developing bacterial vaginosis.

While the condition is more common in women with multiple sex partners, it is not believed to be contagious or entirely related to sexual activity since it is the result of overgrowth or imbalance in the bacteria normally present in the vagina. Moreover, women who have not had sexual activity can develop bacterial vaginosis.

What Are the Signs and Symptoms of Bacterial Vaginosis?

Vaginal discharge, often with a foul-smelling odor, is typically the only symptom of bacterial vaginosis. The discharge has been described as thin and gray to white in color. It is difficult to determine how much discharge represents an abnormal amount, since all women can have varying amounts of vaginal discharge. In general, any discharge that is in excess of normal for a particular woman can be regarded as abnormal. Many women with bacterial vaginosis have no symptoms at all.

When Should You Call Your Doctor If You Think You Have Bacterial Vaginosis?

If you experience an unusual or excessive vaginal discharge, a visit to your health-care professional is recommended so that more serious conditions can be ruled out, such as infection with Chlamydia or gonorrhea. The unpleasant symptoms of bacterial vaginosis also can be effectively treated.

Which Types of Doctors Treat Bacterial Vagniosis?

Gynecologists typically treat bacterial vaginosis, although primary care providers also may treat the condition.

What Exams and Tests Diagnose Bacterial Vaginosis (BV)?

The medical history and physical examination are the first steps in helping to distinguish bacterial vaginosis from more serious conditions.

After taking a medical history, the health care professional will perform a pelvic exam. During the exam, the doctor will observe the vaginal lining and cervix and will perform a manual examination of the ovaries and uterus. Also during the exam, the doctor may collect samples for examination under a microscope or for other studies to rule out the presence of sexually transmitted infections (STDs).

Examination of the discharge under the microscope can help distinguish bacterial vaginosis from yeast vaginitis (candidiasis) and trichomoniasis (a type of sexually transmitted infection). A sign of bacterial vaginosis under the microscope is an unusual cell referred to as a "clue cell." Women with bacterial vaginosis also have fewer of the type of normal vaginal bacteria called lactobacilli. The vaginal pH (degree of acidity or alkalinity) may also be measured, since a vaginal pH greater than 4.5 also suggests bacterial vaginosis.

A so-called "whiff test" with potassium hydroxide (KOH) liquid is sometimes performed whereby a drop of KOH testing liquid is mixed with a drop of vaginal discharge. If bacterial vaginosis is present, a fishy odor can result.

What Is the Treatment for Bacterial Vaginosis?

Medical treatment for bacterial vaginosis involves antibiotics taken either orally or applied locally to the vagina. Since bacterial vaginosis is not believed to be a sexually transmitted condition, treatment of male sex partners is typically not necessary.

Medications that cure bacterial vaginosis (antibiotics)

Several antibiotics are effective in the treatment of bacterial vaginosis.

  • Metronidazole (Flagyl) taken by either oral (pill) form or as a vaginal gel (Metrogel) is an effective treatment.
  • A vaginal clindamycin cream (Cleocin) is also an effective option.
  • Tinidazole (Tindamax) is an antibiotic that appears to have fewer side effects than metronidazole and is also effective in treating bacterial vaginosis.

Do I Need to Follow Up With My Doctor?

A return visit to a health-care professional is recommended if the patient's symptoms do not resolve after antibiotic treatment or if symptoms return. Recurrent bacterial vaginosis may develop in the same woman after she has been treated, so it is important to see a health-care professional if symptoms persist or recur. Up to 50% of women who are treated will develop a recurrence of symptoms in the year following treatment.

Can Bacterial Vaginosis Be Prevented?

Because the exact reasons for bacterial overgrowth in the vagina are unknown, it may not be always possible to prevent bacterial vaginosis. However, by decreasing certain behaviors (smoking, vaginal douching, and having multiple sex partners) a woman can reduce her chances of developing the condition.

What is the outlook for a woman with bacterial vaginosis?

Bacterial vaginosis can be effectively treated with antibiotics. The presence of bacterial vaginosis does appear to increase a woman's risk for acquiring sexually transmitted infections (STDs), including HIV.

In pregnancy, bacterial vaginosis is associated with an increased risk of premature labor and premature birth as well as infection of the uterus after delivery. However, studies have shown that screening and treatment of all pregnant women without symptoms for bacterial vaginosis did not reduce the incidence of preterm delivery. So routine screening of all pregnant women is not recommended. However, certain groups of women at higher risk for preterm birth may benefit from screening even when no symptoms are present, and research is ongoing to further characterize and determine the need for screening in women at higher risk for preterm birth.

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What you should know

Up to 75% of women will experience an inflammatory condition of the vagina at some point in their lives. Medically known as vaginitis, inflammation in the vaginal area is a common condition resulting from multiple causes. Two of the most common causes of vaginitis are yeast infection and bacterial vaginosis.

Reviewed on 7/2/2021

Girerd, PH, MD, et al. Bacterial Vaginosis." Medscape. Updated: Oct 25, 2018.<>