Updated December 2016.
What is bacterial vaginosis?
Bacterial vaginosis is an overgrowth of several bacteria that normally exist in the vagina. In the past, bacterial vaginosis was called nonspecific vaginitis, Gardnerella vaginitis, Haemophilus vaginitis, Corynebacterium vaginitis, and anaerobic vaginosis. Bacterial vaginosis is generally not thought to be a sexually transmitted infection (STI), because it occurs in people who are and are not sexually active. We include it here because it is more common in people with vaginas who are sexually active and because the symptoms of bacterial vaginosis can be similar to the symptoms of other STIs.
What causes it?
The exact cause of bacterial vaginosis is unknown. There could be a variety of causes. No single organism causes it. It is a condition in which the natural balance of organisms found in the vagina changes. The healthy vagina normally contains a variety of bacteria. One kind of bacteria, known as lactobacillus, is particularly important. Lactobacilli keep the vagina slightly acidic to help reduce the growth of potentially harmful organisms. People who have bacterial vaginosis lose this protection and have both a large increase in the number of potentially harmful bacteria and a large decrease in the numbers of normal, protective lactobacilli in their vagina. This change in numbers and kinds of bacteria is believed to be the cause of bacterial vaginosis.
Is it common?
Bacterial vaginosis is widely believed to be even more common than yeast infections. It is the most frequently occurring vaginal infection affecting from 10% to 64% of the people with vaginas at any given time.
What are the symptoms?
Nearly half of all people with bacterial vaginosis will experience no symptoms at all. When someone does have symptoms, the most common complaint is a foul or "fishy" smelling vaginal odor. This odor frequently increases following intercourse. In a recent survey of medical providers, more than half said that the most common complaint from people with bacterial vaginosis is vaginal odor. Another common symptom is an excessive white or gray discharge with a milk-like consistency that can stain undergarments.
How is it diagnosed?
A medical provider can detect bacterial vaginosis by examining vaginal secretions under a microscope and checking pH. Occasionally, bacterial vaginosis will be incidentally picked up on a routine Pap smear.
How is it treated?
Your medical provider may prescribe a medicine you can use vaginally for a prescribed length of time. Sometimes bacterial vaginosis is treated with oral medications. It is important to take the medicine as directed and to abstain from sexual contact until the treatment is completed.
Are there any complications associated with bacterial vaginosis?
Bacterial vaginosis increases the risk of developing pelvic inflammatory disease, a condition which may require hospitalization. Complications, including infertility, pelvic pain and ectopic pregnancy, may also occur with pelvic inflammatory disease. There is also an increased risk of developing bacterial vaginosis following gynecological surgery.
Does my partner need to be treated?
Since bacterial vaginosis is not thought to be caused by sexual intercourse, most medical providers will not treat your sexual partner. If your infection should return, your medical provider may recommend treating your partner.
What can I do to help prevent recurrences?
As with yeast infections and the common cold, many people will experience recurrences of bacterial vaginosis. It is unclear why or how these recurrences or relapses occur. Some general suggestions for good vaginal health include:
Avoid spreading bacteria from the rectum to the vagina. After a bowel movement, wipe from front to back, away from the vagina.
Clean the vulva thoroughly and keep it dry
Avoid douching and using irritating agents such as feminine hygiene sprays and harsh soaps.
Avoid tight jeans, panty hose without a cotton crotch or other clothing that can trap moisture.
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