The cause of Bacterial Vaginosis (BV) is not really understood.

BV is the most common cause of unusual vaginal discharge which develops when the normal environment of the vagina changes. One in three women will get it at some time.

It is not a sexually transmitted infection but can develop after you have had sex. Women who are sexually active and have had a change of partner are more likely to have it, including women in same-sex relationships.

BV can occur if you:

  • Use medicated or perfumed soaps, bubble bath or shower gel
  • Put antiseptic liquids in the bath
  • Douche or use vaginal deodorant
  • Use strong detergents to wash your underwear
  • Smoke

Hormonal changes during the menstrual cycle, semen in the vagina after sex without a condom, an intrauterine contraceptive device (COIL) and genetic factors may also play a part.

Men do not get BV.