Cause
BV is a sign of a change in the growth of vaginal bacteria. The resulting chemical imbalance occurs when different types of bacteria outnumber the normal “good,” or beneficial, ones. Instead of Lactobacillus (a type bacteria that normally lives in the vagina) being most common, increased numbers of bacteria such as Gardnerella vaginalis, Bacteroides, Mobiluncus, and Mycoplasma hominis inhabit the vaginas of women with BV.