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Quick Facts

Bacterial Vaginosis (BV)


The Manual's Editorial Staff

Last full review/revision Jun 2021| Content last modified Jun 2021
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What is the vagina?

Your vagina connects your uterus (where a baby grows when you're pregnant) to the outside of your body. Some people call it the birth canal. Your vulva is the area between your legs on the outside of your body. Many people mistakenly refer to the vulva as the vagina.

What is bacterial vaginosis (BV)?

BV is a very common vaginal infection that happens when the good and bad bacteria (germs) in your vagina are out of balance. Your vagina normally has many kinds of bacteria in it. Most are good bacteria. The good bacteria help keep your vagina healthy by limiting the growth of bad bacteria. If you have BV, the amount of good bacteria goes down and the amount of bad bacteria goes up.

  • You'll likely have a vaginal discharge (thick liquid coming out of your vagina) that's gray or white and smells fishy

  • BV usually goes away a few days after starting medicine, but it often comes back

  • If untreated, BV can cause serious health problems (such as PID) and complications if you're pregnant

What causes BV?

BV is caused by a change in the amount of different bacteria in your vagina. No one knows what causes the change or if the problem can come from having sex. You can get BV even if you've never had sex. But it is more common if you:

  • Have an STD (sexually transmitted disease)

  • Have several sex partners

  • Use an IUD (intrauterine device) for birth control

What are the symptoms of BV?

The main symptoms are:

  • Thin vaginal discharge that's gray or white

  • Discharge that smells fishy—this smell may be stronger after having sex and during your monthly periods

How can my doctor tell if I have BV?

Your doctor will suspect BV based on your symptoms. To tell for sure, your doctor will do a pelvic exam. During a pelvic exam, your doctor first looks at your vulva and then looks inside your vagina. In order to see inside, your doctor will hold your vagina open with a small instrument called a speculum. Your doctor will take a sample of your discharge (if you have any) to test it.

How do doctors treat BV?

  • If you’re not pregnant, doctors will prescribe antibiotics to take by mouth

  • If you’re pregnant, doctors will prescribe a medicated gel or cream to put in your vagina

  • If the infection comes back, you may need to take the medicine for a long time

Your birth control method may not work while you're being treated. Some medicated creams used to treat BV weaken condoms and diaphragms.

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