Bacterial vaginosis

Bacterial vaginosis is not a sexually transmitted infection. It's an imbalance of the usual bacteria found in the vagina. It can cause an abnormal vaginal discharge which can smell fishy and unpleasant.

How do you get bacterial vaginosis?

Bacteria called lactobacilli naturally live in your vagina and stop other bacteria from growing there.

Sometimes the balance of these bacteria changes. If this happens you can develop bacterial vaginosis.

Bacteria other than lactobacilli overgrow in the vagina and can cause symptoms.

Bacterial vaginosis can’t be passed from person to person. But it's more common in people who are sexually active.

Other things that may increase your risk of getting it include:

  • having a new sexual partner
  • having multiple sexual partners
  • smoking
  • using scented soaps or perfumed bubble bath
  • putting antiseptic liquids in the bath
  • douching (washing or cleaning out the vagina with water or other fluids)
  • using vaginal washes or deodorant
  • using strong detergents to wash your underwear

Symptoms of bacterial vaginosis

Often there are no symptoms of bacterial vaginosis. Some women may notice a change in the normal secretions from the vagina.

This discharge will usually be white or grey, thin or watery and have a strong, unpleasant fishy smell. This can be more noticeable during and after sex, and during periods.

Bacterial vaginosis does not usually cause itching or irritation.

Testing for bacterial vaginosis

If you think you have bacterial vaginosis you can make an appointment with your GP or local sexual health services.

Your nurse or doctor may perform an internal examination to check the vagina for signs of bacterial vaginosis and use a swab to collect a sample of the discharge from your vagina.

A swab looks a bit like a cotton bud and collecting a sample only takes a few minutes. Although not painful, it may be a little uncomfortable for a moment.

A specially coated paper may be used to test the pH (alkaline/acid balance) of your vagina.

Sometimes a diagnosis can be made straightaway because of the distinctive appearance of the discharge. Sometimes the sample will be sent to a lab for testing.

Treatment for bacterial vaginosis

Bacterial vaginosis is treated with antibiotics. An antibiotic cream or gel to use in the vagina may be given instead of antibiotic tablets by mouth.

While you're there, make sure you tell the doctor or nurse if you:

  • are pregnant
  • think you might be pregnant
  • are breastfeeding

These may affect the type of treatment you're given.

Bacterial vaginosis recurrence

Bacterial vaginosis can recur. Most recurrences will respond to the treatments described.

Avoiding passing on bacterial vaginosis to a partner

You can still have sex while you are being treated for bacterial vaginosis because it's not sexually transmitted. However, antibiotics and cream can affect condoms and other contraception. Speak to your doctor or pharmacist who can give you further information.

Reducing the risk of getting bacterial vaginosis

The causes of bacterial vaginosis are not fully understood, so it may not be possible to completely prevent it. However, you may be able to lower your risk of developing it.


  • do not use scented soaps and perfumed bubble bath
  • do not use vaginal deodorant
  • do not douche (washing or cleaning out your vagina)
  • do not put antiseptic liquids in the bath
  • do not use strong detergent
  • avoid triggers that you've identified yourself

Last updated:
02 December 2022