Bacterial vaginosis


Photo of a couple taking a stroll along the beach
PantherMedia / Graham Oliver

In bacterial vaginosis (sometimes abbreviated as BV), much larger than normal numbers of grow inside of the vagina.

This increase in is usually not dangerous and it often goes unnoticed, but it can cause a strong-smelling vaginal discharge and be very unpleasant. It also increases the risk of vaginal . Antibiotics can provide effective treatment.


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. 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 of the vagina). In that case the area around the vagina is usually reddened and the mucous lining of the vagina is swollen. There may also be problems when urinating (peeing) or during sex.


The vagina mostly contains lactic acid (LAB). Together with other 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 is caused by an imbalance in this acidic environment: The number of lactic acid drops and other vaginal flora can reproduce quickly. Bacterial vaginosis is most commonly caused by called Gardnerella vaginalis.

Risk factors

The risk of bacterial vaginosis is higher in women who are very sexually active and have a new partner or switch partners frequently.

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

Prevalence and outlook

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


If there is an imbalance in the vaginal flora, it's easier for other germs to grow there. This is why bacterial vaginosis can cause vaginal , and then also lead to infections in the womb (uterus) and fallopian tubes. The risk of contracting sexually transmitted diseases also increases.

Vaginal infections can also slightly increase the risk of complications such as early contractions, miscarriage, or premature birth in pregnant women.


It's not always possible to tell bacterial vaginosis from other types of vaginal infections based only on the symptoms. To diagnose vaginosis, a gynecologist examines the vagina and takes a sample of the secretion. This sample (“smear”) can be used to measure the pH level to find out what types of it contains. Samples from women with bacterial vaginosis usually have high levels of gardnerella .


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

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

Some women also try things like putting tampons that have been soaked in tea tree oil or natural yogurt in their vagina to create a more acidic environment for the vaginal flora, but there has not yet been any research about how effective or safe these kinds of home remedies are.

Amaya-Guio J, Viveros-Carreno DA, Sierra-Barrios EM, Martinez-Velasquez MY, Grillo-Ardila CF. Antibiotic treatment for the sexual partners of women with bacterial vaginosis. Cochrane Database Syst Rev 2016; (10): CD011701.

Centers for Disease Control and Prevention (CDC). Sexually Transmitted Diseases Treatment Guidelines. June 05, 2015. (Morbidity and Mortality Weekly Reports; Band 64).

Deutsche Gesellschaft für Gynäkologie und Geburtshilfe (DGGG). Bakterielle Vaginose (BV) in Gynäkologie und Geburtshilfe (S1-Leitlinie). AWMF-Registernr.: 015-028. August 2010.

Hainer BL, Gibson MV. Vaginitis. Am Fam Physician 2011; 83(7): 807-815.

Oduyebo OO, Anorlu RI, Ogunsola FT. The effects of antimicrobial therapy on bacterial vaginosis in non-pregnant women. Cochrane Database Syst Rev 2009; (3): CD006055.

Spence D, Melville C. Vaginal discharge. BMJ 2007; 335(7630): 1147-1151.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

Comment on this page

What would you like to share with us?

We welcome any feedback and ideas. We will review, but not publish, your ratings and comments. Your information will of course be treated confidentially. Fields marked with an asterisk (*) are required fields.

Please note that we do not provide individual advice on matters of health. You can read about where to find help and support in Germany in our information “How can I find self-help groups and information centers?

Updated on August 9, 2018
Next planned update: 2021


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

How we keep you informed

Follow us on Twitter or subscribe to our newsletter or newsfeed. You can find all of our films online on YouTube.