What Is Bacterial Vaginosis?

Bacterial vaginosis (BV) is a mild infection in the vagina. It develops when there's an imbalance between the "good" bacteria in the vagina that are helpful and the "bad" bacteria that can cause problems.

Bacterial vaginosis may cause pain, itching, and a bad-smelling discharge. But most girls with BV don't notice any symptoms — and that's not necessarily a good thing. Symptoms alert us to signs of trouble. Girls who don't know they have BV might not get treated for it. BV may be mild, but if it isn't treated it can lead to other problems.

BV is the most common vaginal infection affecting young women. Although it's not considered a sexually transmitted disease (STD), the chances of developing bacterial vaginosis seem to increase with the number of sexual partners a woman has.

You don't need to be having sex to get BV, though. Girls who've never had sex also can get it.

What Causes It?

Normally, a lot of good, healthy bacteria live in the vagina along with a small amount of potentially harmful bacteria. But sometimes this balance can be upset by things like douching. That can lead a girl to develop bacterial vaginosis.

Although medical experts don't know for sure what causes BV, they do know that certain things can make the infection more likely, such as:

• douching
• new sex partners or many different sex partners (male or female)
• cigarette smoking

You can't get BV from things like toilet seats, sheets and towels, or swimming pools.

How Do You Know If You Have It?

Many girls don't see any signs of BV. But those who do might notice:

• an abnormal white or gray vaginal discharge that's thin, with a bad, fishy smell that's more noticeable during a girl's period or after sex
• pain while peeing
• itching in and around the vagina

It's normal to have vaginal discharge at different points during your menstrual cycle. But if you notice any discharge or other vaginal symptoms that don't seem normal, contact your doctor.

What Happens at the Doctor's Office?

You'll start by talking with a doctor or nurse practitioner about your medical history and symptoms. Then he or she will examine you, and probably use a cotton swab to collect a sample of vaginal fluid. This sample will then be tested in the office or in a lab.

It's usually possible to diagnose BV without doing an internal pelvic exam.

Treating BV

The usual treatment for BV is prescription antibiotics (pills, vaginal creams, or suppositories). Because BV can come back, a girl may need to take more than one series of antibiotics. Even if you feel better partway through taking the antibiotics, you'll need to take all the pills (or use all the cream or suppositories).

Your health care provider should let you know about any restrictions needed while taking the antibiotic. For example, some medications can weaken condoms and diaphragms (even after the treatment is finished). With other medications, people can't drink alcohol. Ask if there's anything you should avoid while taking your medication.

If a girl is having sex, her male sex partners probably won't have to get treated, but female partners will.

Can It Be Prevented?

It's not always possible to prevent BV. But these things can lower a girl's chance of getting it:

• don't use douches
• abstain from sex
• if you decide to have sex, always use a condom and limit the number of sex partners

Complications

Most of the time, BV goes away without any complications when properly treated. But if it's not treated, BV can increase a girl's chances of certain health problems:

• Increased chance of getting an STD: Girls with BV are more likely to get STDs like herpes, chlamydia, gonorrhea, and HIV.
• Increased chance of pregnancy complications: When BV isn't treated, a woman may have more problems when she gets pregnant, such as premature birth, low birth weight, infection, and possibly miscarriage.

Infections like BV are one reason why girls who are having sex need to get regular gynecological checkups and STD tests. Even if a girl doesn't know that she has an infection, doctors and nurse practitioners can diagnose and treat it to help prevent complications.

Reviewed by: Larissa Hirsch, MD
Date reviewed: July 2011