Bacterial vaginosis

Bacterial vaginosis (BV) – is caused by changes to the balance of natural bacteria inside the vagina. It’s the most common cause of unusual vaginal discharge - the fluid that comes from the vagina.

It’s not usually serious. But it does need treatment. It can increase your risk of getting some STIs, like chlamydia. This is because it lowers your body's natural defences by making your vagina less acidic.

If you’re pregnant there’s a small chance having BV could cause complications.

What causes bacterial vaginosis?

The vagina naturally contains many different bacteria. When some types increase, the balance gets thrown off. This can cause bacterial vaginosis.

Although it’s not an STI, you’re more likely to get it if you’re sexually active. You're also more likely to get it if you smoke.

What are the symptoms?

Around half the people who have bacterial vaginosis will not get any symptoms. It does not carry any threat to your health, or a pregnancy if you have no symptoms.

BV does not usually cause any vaginal soreness or itching. If you have these symptoms it’s a good idea to get it checked, as there could be another cause.

It does usually affect vaginal discharge. You might notice discharge:

  • has a strong fishy smell, particularly after sex

  • becomes a white or grey colour

  • becomes thin and watery

Testing and treatment

You can get tested for bacterial vaginosis at a sexual health clinic or by your GP.

Your clinician will ask you about your symptoms and may examine your vagina. In some cases, a small sample of vaginal discharge will be taken to be tested to help diagnose your symptoms.

BV can usually be treated successfully with a short course of antibiotics. These might be tablets or an antibiotic gel that you apply inside your vagina. You can get treatment from your GP, local sexual health clinic and pharmacies.

Some creams and gels can weaken the latex in condoms and diaphragms. If you use these types of contraception, mention it to your doctor or pharmacy when you get treatment.

Pregnant women who have symptoms should seek advice as soon as they can.

It’s common for people who’ve had bacterial vaginosis to get it again. More than half of those who are successfully treated will find their symptoms return, usually within 3 months.

If you get recurring BV – having it more than 4 times a year – you may be referred to a genitourinary medicine (GUM) specialist to discuss longer-term treatments.

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