Bacterial vaginosis - Diagnosis 

See your GP as soon as possible if you have any abnormal discharge from your vagina.

It is important to get bacterial vaginosis (BV) diagnosed to rule out other infections, such as trichomonas vaginalis or gonorrhoea. These can both cause abnormal vaginal discharge.

If you prefer, you could visit a sexual health clinic for a diagnosis, instead of your GP. Sexual health clinics are sometimes known as genitourinary medicine (GUM) clinics. They are usually located in a hospital or are part of another health centre. Find your nearest sexual health service.

Examination

Your GP or healthcare professional may diagnose BV from a description of your symptoms and by examining your vagina. In particular, they will look for:

• a thin, greyish discharge
• an unpleasant smell

In some cases, this may be enough to confirm your diagnosis. However, if you are sexually active and may have a sexually transmitted infection (STI) instead of BV, you may need further tests. 

Tests

A sample of cells may be taken from the wall of your vagina using a plastic loop or swab. A swab looks a bit like a cotton bud but is smaller, soft and rounded.

The swab or loop picks up samples of discharge and cells. It only takes a few seconds and is not usually painful, although it may be slightly uncomfortable for a moment.

The samples are examined to check for BV. The result may be available immediately or the sample may be sent to a laboratory, in which case the result will usually be available within a week.

The pH (alkaline/acid balance) of your vagina may also be measured. A swab will be taken from inside your vagina and wiped over a piece of specially treated paper. The paper changes colour depending on the pH level. A pH level higher than 4.5 is an indication that you may have BV.

These tests and all sexual health services are free on the NHS. They are available to everyone, regardless of age. Treatment is also free, but if you go to your GP, you may have to pay a prescription charge.