Bacterial vaginosis is a vaginal condition caused by a change in the balance of bacteria that normally live in the vagina. Although its "fishy" smell and thin, grayish white vaginal discharge are only bothersome for some women, bacterial vaginosis has been linked to pregnancy complications and to infection after a pelvic surgery or procedure.

About half of women with bacterial vaginosis have no symptoms. Women who notice symptoms report that symptoms tend to be worse after sex and following a menstrual period.

Bacterial vaginosis is treated with antibiotic medicine taken by mouth or with a medicated cream, gel, or ovules that are put inside the vagina. Treating male sex partners of affected women is not necessary or effective.