Bacterial vaginosis (BV) is a condition that occurs when something disrupts the vagina’s natural bacterial balance, also called vaginal flora. The microorganisms that live in the vagina are necessary for maintaining normal vaginal pH and the healthy status quo. They also take up space to ensure invaders can’t settle there. When the balance goes awry, you can have an overgrowth of “bad” kinds of bacteria called anaerobes. This overgrowth can sometimes lead to vaginal inflammation or vaginitis.