Bacterial vaginosis, sometimes called BV, is a very common vaginal infection. It is not a sexually transmitted infection (STI) although it may be caused as a result of semen in the vagina after sex without a condom. Men do not get BV.

Signs and symptoms

Often there are no symptoms but some women may notice:

  • A change in the normal discharge from the vagina.
  • Discharge may increase and become thin and watery and have a strong fishy smell, especially after sex.

Getting it

BV is more likely to occur in women when the vagina’s pH (how acidic or alkaline it is) is altered and becomes more alkaline. How you get it is not really understood although it may be caused by:

  • Using perfumed bubble bath or soap.
  • Douching or using vaginal deodorants.
  • Using a strong detergent to wash your underwear.
  • Smoking.

Diagnosis & treatment

A doctor or a nurse will take a swab from the inside of the vagina and a sample of pee may be taken. Treatment for BV is simple and involves taking antibiotic tablets. There are various types of antibiotics available and you should discuss which would best suit you with the doctor or nurse, as some should not be taken if you are pregnant, breastfeeding or on the pill. A cream to use in the vagina may be given instead. Some creams can weaken latex condoms, diaphragms or caps, so alternative protection should be used during treatment. Again, your doctor or nurse will advise.

Long-term effects

For many women BV goes away without being treated. BV will not affect your chances of getting pregnant although if you are pregnant it may cause problems such as miscarriage, premature birth or the baby being born underweight.

Treatment when pregnant or breastfeeding will not harm the baby, but do let your doctor or nurse know.

If you think you may have BV, contact your local NHS sexual health clinic (also known as a GUM clinic) and make  an appointment. It’s easy and completely confidential.

For more information on sexual health (including HIV), call the Sexual Health Line free (from the UK) on 0800 567 123, textphone (for people with hearing impairments) 0800 52 361 or phone your local NHS sexual health clinic.