Bacterial vaginosis (BV)

Bacterial vaginosis (BV)

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in women of child bearing age.  BV is not classed as a sexually transmitted infection (STI), but women who are sexually active are more likely to develop BV.

The vagina naturally contains many different bacteria.  BV occurs when there is an imbalance in the usual bacteria in the vagina.


Around half of women with BV have no symptoms.  In these cases, the condition does not pose any threat to your health or pregnancy.

If you have BV you may notice that your vaginal discharge:

  • has a strong fishy odour, particularly after sex
  • is white or grey
  • is thin or watery

BV does not usually cause vaginal soreness or itching.


BV can usually be successfully treated using a short course of antibiotic tablets or an antibiotic gel that you use inside the vagina.

However, BV may clear up without any treatment.  For most women there are no complications from BV, so treatment is only recommended if it’s bothering you or if you are having certain gynaecology procedures such as a surgical abortion.

Pregnant women who have BV with symptoms should be treated, as there is a small risk of complications, including miscarriage or premature birth.


The best way to prevent BV is not known but avoiding anything that upsets the natural balance of bacteria in the vagina may help.  This includes avoiding scented soaps, bubble baths, vaginal deodorants, feminine washes, and douching (cleaning out the vagina).

Having sex with a condom can also sometimes help as the semen does not go into the vagina.

To find out more about BV click here: NHS Choices - bacterial vaginosis