Bacterial Vaginosis (BV)

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BV is caused by an imbalance of the bacteria that normally live in the vagina. The vagina is naturally colonised by a bacteria called lactobacilli that causes the environment to be acidic. Substances and activities that make the vagina less acidic may cause the growth of other bacteria that causes odour.  Sperm, lubricants, blood and soap are alkaline (opposite of acidic), so if these substances are frequently inside the vagina for long periods of time, then BV may develop.

Signs and Symptoms

  • A watery white or grey discharge
  • A strong or unpleasant ‘fishy’ odour
  • Mild irritation of the vagina
  • Often no symptoms


While BV is not thought to be transmitted sexually, it does appear to be more common in people who are sexually active.

The exact cause of BV remains unknown; however, semen is alkaline and capable of changing the normal acid environment in the vagina and bacterial imbalances. Douching can also cause pH and bacterial imbalances in the vagina.


If BV is diagnosed, it is not always treated. If the person is not pregnant or experiencing any symptoms, then no treatment is given. The aim of treatment is to restore the acidity of the vagina. There are both medical and self-administered treatments which will do this, including:

  • Vaginal pessaries – available from the chemist
  • Salt water vaginal washes
  • Prescribed tablets from a doctor (the full course of the tablets must be completed)
  • Prescribed vaginal creams from a doctor

Recurrence is possible even after treatment.