Bacterial Vaginosis

The vagina contains many types of bacteria. Bacterial vaginosis occurs when the normal balance of bacteria in the vagina is disrupted. Bacterial vaginosis is not a sexually transmitted infection (STI), but having new or multiple sex partners can change the balance of bacteria in the vagina.

If left untreated, bacterial vaginosis may increase the risk of getting a sexually transmitted infection such as chlamydia, gonorrhea or HIV.


Many people with bacterial vaginosis do not have symptoms. If symptoms occur, they can include:

  • Gray discharge
  • Foul-smelling vaginal odor (especially after sex)
  • Itching or swelling in or around the vagina and
  • Burning during urination


Avoid vaginal douching — this may lead to infections, such as bacterial vaginosis. Having new or multiple sex partners likely increases the risk of bacterial vaginosis.


Your health care providers can test for bacterial vaginosis with a sample of vaginal fluid.


Bacterial vaginosis is treated with pills or vaginal gel.

Sex Partners

Bacterial vaginosis is not an STI, so you will not spread the infection to your sex partner(s). However, if a partner experiences any symptoms of bacterial vaginosis, they should see their health care provider.

Bacterial Vaginosis in Pregnancy

Pregnant people who experience symptoms of bacterial vaginosis should be tested as soon as those symptoms appear. Bacterial vaginosis can cause premature birth and infection of the womb after delivery.

Additional Resources

More Information