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Bacterial vaginosis (BV)

Bacterial vaginosis (BV) is a common condition which sees the balance of bacteria inside the vagina becomes disrupted.

BV doesn't usually cause any vaginal soreness or itching, but often causes unusual vaginal discharge. If you have the condition, your discharge may:

  • Develop a strong fishy smell, particularly after sexual intercourse
  • Become white or grey
  • Become thin and watery

BV isn't serious for the vast majority of women, although it may be a concern if symptoms of BV develop in pregnancy and you have a history of pregnancy-related complications.

Around half of women with bacterial vaginosis have no symptoms.

Noticing abnormal discharge

If you notice a regular abnormal discharge you may want to make an appointment at one of our clinics so that one of our nurses or doctors can examine you and take some tests for the laboratory.

Please note: We have a microscopist at some of our weekly clinics who can look under a microspore and often diagnose trichomoniasis there and then. This enables us to to provide you with treatment to take away with you. Clinics with a microscopist:

Every Tuesday and Friday, 9.00am - 12noon
Arrowe Park Hospital, 2nd Floor, Upton CH49 5PE

Every Thursday, 1.00pm - 3.00pm
Gemini Centre, St Catherine's Health Centre, 2nd Floor, Green Wing, Derby Road, Birkenhead CH42 0LQ

Why BV happens

The vagina naturally contains a mix of many different bacteria. In cases of BV, the number of certain bacteria increases, affecting the balance of chemicals in the vagina.

What leads to these changes in the levels of bacteria is not clear. BV isn't classified as asexually transmitted infection (STI), but you're at a higher risk of developing the condition if you're sexually active.

Women with BV may be able to pass the condition to other women they have sex with, although it's not clear how this happens.

There's no evidence to suggest the bacteria causing BV can affect male sexual partners.

There are also a number of other factors that can increase your risk of developing BV. These include:

BV is more common in women who use a coil for contraception and those who perform vaginal douching (cleaning out the vagina).


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

In most cases, you'll be prescribed antibiotic tablets to take twice a day for five to seven days.

Download the Family Planning Association thrush and bacterial vaginosis leaflet