Bacterial vaginosis (BV) is a common cause of unusual vaginal discharge. BV is not a sexually transmitted infection (STI) but it can increase your risk of getting an STI such as chlamydia.

Check if you have bacterial vaginosis

The most common symptom of bacterial vaginosis is unusual vaginal discharge that has a strong fishy smell, particularly after sex.

You may notice a change to the colour and consistency of your discharge, such as becoming greyish-white and thin and watery.

However, 50% of women with bacterial vaginosis don’t have any symptoms.

Bacterial vaginosis doesn’t usually cause any soreness or itching.

If you’re unsure it’s BV check for other causes of unusual vaginal discharge.

See a GP or go to a sexual health clinic if you think you have BV.

The condition is not usually serious but if you do have BV you will need to be treated with antibiotics.

It is also important to seek treatment if you are pregnant as there is a small chance that BV can cause complications with pregnancy.

Treatment for bacterial vaginosis

Bacterial vaginosis is usually treated with antibiotic tablets or gels or creams. These are prescribed by your GP or sexual health clinic.
If you have a same-sex partner, they may also need treatment.

Recurring bacterial vaginosis

It’s common for BV to come back, usually within 3 months.
You’ll need to take treatment for longer (up to 6 months) if you keep getting BV (you get it more than twice in 6 months). Your GP or sexual health clinic will recommend how long you need to treat it.

They can also help identify if something is triggering your BV, such as sex or your period.


Things you can do yourself

To help relieve symptoms and prevent bacterial vaginosis from returning:

  • do use water and plain soap to wash your genital area
  • do have showers instead of baths


  • do not use perfumed soaps, bubble bath, shampoo or shower gel in the bath
  • do not use vaginal deodorants, washes or douches
  • do not put antiseptic liquids in the bath
  • do not use strong detergents to wash your underwear
  • do not smoke

What causes bacterial vaginosis

Bacterial vaginosis is caused by a change in the natural balance of bacteria in your vagina. What causes this to happen isn’t fully known, but you’re more likely to get it if:

  • you’re sexually active (but women who haven’t had sex can also get BV)
  • you’ve had a change of partner
  • you have an IUD (contraception device)
  • you use perfumed products in or around your vagina

BV is not classed as an STI, even though it can be triggered by sex. A woman can pass it to another woman during sex.

You’re more likely to get an STI if you have BV. This may be because BV makes your vagina less acidic and reduces your natural defences against infection.

Bacterial vaginosis in pregnancy

If you develop bacterial vaginosis in pregnancy, there’s a small chance of complications, such as premature birth or miscarriage.

However, BV causes no problems in the majority of pregnancies. Speak to your GP or midwife if you’re pregnant and your vaginal discharge changes.