Bacterial vaginosis (BV) is a condition where the normal, healthy balance of “good” bacteria in the vagina becomes unbalanced and there is an overgrowth of harmful bacteria. In other words, the harmful bacteria outnumber the beneficial bacteria. Bacterial vaginosis is the most common vaginal infection among women of childbearing age.
Although behaviors including having a new sexual partner or multiple partners, using an IUD (intrauterine device), and douching may increase risk of BV, it’s possible for any women to develop the condition—even if she has never had intercourse.
Bacterial vaginosis can generally be treated effectively and rarely causes complications. Certain risks, however, have been observed. These include an association between pelvic inflammatory disease, infertility, and tubal (ectopic) pregnancy. As well, BV can increase susceptibility to other sexually transmitted infections (such as chlamydia, gonorrhea, and HIV). The risk that a woman with HIV will pass HIV to her sex partner is also greater if she has BV. Bacterial vaginosis can increase the risk of infection following surgical procedures such as hysterectomy or abortion. Among pregnant women, BV can raise risk of preterm delivery and low birth-weight babies.
Bacterial vaginosis may not cause symptoms, so some women may not know they have the condition. In other women, however, BV does cause the following symptoms:
- Abnormal, foul-smelling discharge that is white or gray in color
- Pain during urination
- Itching or burning around the vagina
To diagnose BV, your doctor will take a sample of vaginal fluid, which will be tested in the laboratory. Bacterial vaginosis is diagnosed when an overgrowth of the bacteria associated with BV is detected.
If you have BV, your doctor will prescribe antibiotics for treatment. The two antibiotics used to treat BV are metronidazole and clindamycin. Be aware that even after treatment, BV can recur.
Treatment of BV can relieve discomfort. It’s also important to treat the condition to avoid the associated complications described earlier in “Overview.”
Bacterial Vaginosis Versus Yeast Infection
Whereas BV is a bacterial infection, a yeast infection, or candidiasis, is a fungal infection that occurs when there is an overgrowth of the fungus Candida. The distinction between the bacterial nature of BV and fungal nature of a yeast infection is important because the two are treated differently. In fact, antibiotic treatment for BV can actually lead to a yeast infection because antibiotics can kill good bacteria in the vagina. Accurate diagnosis (with laboratory testing) of BV and yeast infection is therefore important so that doctors can choose appropriate treatment. Symptoms of BV and yeast infection are similar (genital itching or burning and changes in vaginal discharge in some cases)—therefore only a laboratory test can correctly identify either condition.
Bacterial Vaginosis (BV). Centers for Disease Control and Prevention website. Available at: (Accessed November 2010.)
Bacterial Vaginosis. National Institute of Allergy and Infectious Disease website. Available at: (Accessed November 2010.)