What is bacterial vaginosis (BV)?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

The vagina normally has a balance of mostly "good" bacteria and fewer "harmful" bacteria. Bacterial vaginosis, known as BV, develops when the balance changes. With BV, there is an increase in harmful bacteria and a decrease in good bacteria. BV is the most common vaginal infection in women of childbearing age.

This answer is based on source information from The National Women's Health Information Center.

Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age.

BV has gone by different names in the past, including nonspecific vaginitis and Gardnerella vaginalis vaginitis. BV is simpler to remember, but there is nothing simple about this condition, and it is not harmless, as was once believed.

BV is actually a syndrome resulting from an imbalance in the different types of bacteria in the vagina (also called vaginal "flora"). A healthy vagina has numerous organisms that naturally live there. The vast majority—about 95 percent—belong to a type of bacteria called lactobacillus.

There are several kinds of lactobacillus, at least one of which is responsible for keeping the vagina's pH at normal levels. One hypothesis claims that when these levels become unbalanced, certain microorganisms may overtake the normal flora leading to a low-grade infection that often produces an abnormal vaginal discharge.

This content originally appeared on

Continue Learning about Bacterial Infections

What causes septic arthritis?
Diana MeeksDiana Meeks
Septic arthritis is caused by bacteria, and less commonly viruses or fungi, that spread from an infe...
More Answers
When should a woman be tested for group B strep (GBS) if she is pregnant?
Univ. of Nev. School of Medicine, Family MedicineUniv. of Nev. School of Medicine, Family Medicine
A woman should ask her doctor or nurse for a group B strep (GBS) test when she is 35 to 37 weeks pre...
More Answers
What is septic arthritis?
Dr. Jeanne Morrison, PhDDr. Jeanne Morrison, PhD
Septic arthritis, also known as infectious arthritis, is caused by an infection in a joint. The infe...
More Answers
How Can I Prevent an Antibiotic-Resistant Infection?
How Can I Prevent an Antibiotic-Resistant Infection?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.