Bacterial vaginosis is a condition of which the cause is mostly unknown. Researchers do not know the exact way that the bacteria works and why women contract it.

However, it is understood that your chances of getting BV are higher if you are sexually active. The infection is caused by an imbalance in the types of bacteria present in the vagina, where there is more ‘bad’ bacteria than ‘good’.

On this page, we’ll explain:

What are the causes of BV?

There are several factors that are thought to contribute to bacterial vaginosis, including:

  • having multiple sexual partners
  • douching (inserting water into the vagina)  
  • using lots of different types of soaps and gels on the vagina, or ones which are strongly perfumed
  • smoking
  • and using strong detergents to wash underwear.

Again, it isn’t certain why BV occurs; but the above can make it more likely that someone will develop it.

Is BV preventable?

There’s no way to completely eliminate the risk of BV, however avoiding the above risk factors can help to reduce the chances of it developing.

For most women, BV is a condition that cannot be prevented from returning at a later stage. In fact, it is very common for women to contract it again within 3 months of it being treated. In this eventuality, you may be prescribed antibiotics again and this will usually be sufficient. However, it is possible that repeated courses of treatment may be necessary for several bouts of the infection.

Experts think that the reason treatment is not always effective is because we don’t know enough about the way the bacteria develops.

Can I pass BV onto my partner?

In a female same sex relationship, yes.

It is recommended that if you are a woman in a same-sex relationship, you should both be treated at the same time if one person has symptoms of BV. The infection can be passed on through the shared use of sex toys.

But it can’t be passed on from a woman to a man in heterosexual relationship, because men cannot contract BV. Therefore, a man in a heterosexual relationship with a woman who has BV wouldn’t be advised to seek treatment.

There have been trials analysing the possibility of using a sterilising gel on the penis, to help protect the vagina from developing a bacterial imbalance (and developing BV), but these were not found to be effective.

What to do if you think you have BV

If you have mild symptoms or no symptoms then you may not need treatment. However, if BV is causing symptoms (which you can read more about on our BV symptoms page) then you should consult your doctor. You should be especially wary if you are pregnant or trying to get pregnant.

Page last reviewed:  26/10/2018