Bacterial vaginosis

Bacterial vaginosis is caused by an overgrowth of bacteria in the vagina that are normally rarely found there. This increases the risk of vaginal inflammation. Read more about the symptoms, causes and treatment of this condition.

At a glance

  • Bacterial vaginosis is one of the most common types of vaginal infections.
  • It is estimated that it affects about 5 out of 100 women.
  • Vaginosis is caused by an overgrowth of bacteria in the vagina.
  • At least half of the women who develop bacterial vaginosis do not have any noticeable symptoms.
  • The infection increases the risk of vaginal inflammation.
  • The risk of infection is higher in women who switch sexual partners frequently.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Bacterial vaginosis: woman’s hand holding a vaginal tablet in a plastic pack.

What is bacterial vaginosis?

In bacterial vaginosis, much larger than normal numbers of bacteria grow inside of the vagina.

An infection is usually harmless and it often even goes unnoticed, but bacterial vaginosis can cause a strong-smelling vaginal discharge and be very unpleasant for those affected. It also increases the risk of vaginal inflammation. Antibiotics can provide effective treatment for bacterial vaginosis.

What are the symptoms of bacterial vaginosis?

At least half of the women who develop bacterial vaginosis do not have any noticeable symptoms. When the condition is detected, it is usually by a very unpleasant, thin, grayish-white vaginal discharge that smells strongly of fish and is very unpleasant for a lot of women. This smell is often stronger after sex or during menstruation.

Symptoms like itching, a burning sensation and vaginal dryness are more likely signs of vaginitis (an inflammation of the vagina). In that case the area around the vagina is often reddened and the mucous lining of the vagina is swollen. Vaginal inflammation may also result in problems when urinating (peeing) or during sex.

What causes bacterial vaginosis?

The vagina usually contains mostly lactic acid bacteria. Together with other bacteria they make up the vaginal flora and help to maintain a slightly acidic environment. The right acidity (pH level) can help to protect against germs. Bacterial vaginosis can be caused by an imbalance in the acidic level of the vaginal environment: the number of lactic acid bacteria drops and other bacteria can reproduce quickly. Bacterial vaginosis is most commonly caused by bacteria called Gardnerella vaginalis.

What are the risk factors for bacterial vaginosis?

The risk of infection is higher in women who switch sexual partners frequently.

Excessive intimate hygiene or hormonal changes can also cause an imbalance in the vaginal flora and make bacterial vaginosis more likely.

How common is bacterial vaginosis?

Bacterial vaginosis is one of the most common types of vaginal infection. It is estimated that it affects about 5 out of 100 women. The infection clears up on its own in about one third of women. Treatment is usually needed if it causes symptoms.

It is estimated that approximately 5 out of every 100 women have a vaginal yeast infection.

How is bacterial vaginosis diagnosed?

It’s not always possible for gynecologists to tell bacterial vaginosis from other types of vaginal infections based only on the symptoms and so they take a sample of the vaginal secretion (smear) while examining the vagina. This sample can be used to measure the pH level to find out what types of bacteria it contains. Samples from women with bacterial vaginosis usually have excessively high levels of gardnerella bacteria.

How is bacterial vaginosis treated?

Symptomatic bacterial vaginosis is usually treated with antibiotics to kill the germs. Suitable antibiotics are available in tablet form or as a suppository or cream for direct application in the vagina. It’s not necessary to treat your partner, though – the treatment doesn’t prevent future infection.

Another treatment option is suppositories or capsules containing living lactic acid bacteria. These treatments are designed to protect the vaginal flora and restore the correct balance. There is not yet enough evidence on how well this method works.

Some women also try things like putting tampons that have been soaked in tea tree oil or natural yogurt in their vagina to treat the condition, but there has not yet been enough research about how effective or safe these kinds of home remedies are.

More detailed information on vaginosis and which treatments help can be found at gesundheitsinformation.de.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG). As at:

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