A normal, healthy vagina is home to a variety of different bacteria. However, in Bacterial Vaginosis (BV) the balance is disturbed, and an overgrowth of some of these "natural" bacteria occurs. It’s not entirely clear why this happens. Symptoms can include:

• Thin, gray, white or greenish vaginal discharge
• Foul-smelling/fishy-smelling vaginal odour
• Vaginal itch
• Burning or irritation during urination

Many women with bacterial vaginosis have no signs or symptoms.

BV does not necessarily need to be treated if there are no symptoms- the exception is pregnant women, or women who have recently had gynaecological surgery- in which cases, antibiotic treatment may be recommended to reduce the risk of complications and infection.