Bacterial vaginosis is a form of vaginal inflammation resulting from overgrowth of one of several types of bacteria that are normally present in the vagina. The overgrowth upsets the natural balance of vaginal bacteria.

Bacterial vaginosis can occur in any woman but women that are still in reproductive years are more commonly affected. Unprotected intercourse or frequent douching increase the risk of bacterial vaginosis.


Bacterial vaginosis may present without symptoms; however, the typical symptoms of bacterial vaginosis include:

  • Thin and grayish white vaginal discharge
  • Fishy or foul-smelling vaginal odor (especially after intercourse)
  • Vaginal itching
  • Burning during urination


The cause of bacterial vaginosis is overgrowth of one of several bacteria normally present in the vagina. “Good” bacteria (lactobacilli) usually outnumber “bad” bacteria (anaerobes) in the vagina. However, if there is rapid overgrowth of anaerobes the natural balance of microorganisms in the vagina is disrupted leading to bacterial vaginosis.


Risk factors

The factors that increase the risks for bacterial vaginosis include:

  • Multiple sex partners or a recent partner: Bacterial vaginosis is more likely to occur in women with multiple sex partners or a new sexual partner. It also occurs in women who have sexual partners of the same sex.
  • Douching: Frequent rinsing of the vagina with water or douching can also disturb the natural balance of its environment. This can cause overgrowth of anaerobic bacteria and thus bacterial vaginosis.
  • Natural lack of lactobacilli: In the case that the natural environment of the vagina does not produce sufficient lactobacilli bacteria, the person may be more susceptible to bacterial vaginosis.


It is not typical for bacterial vaginosis to cause complications. However, in certain conditions, bacterial vaginosis can lead to:

  • Preterm birth: Bacterial vaginosis can cause preterm birth and low birth weight babies.
  • Sexually transmitted infections: Bacterial vaginosis increases the risk of sexually transmitted infections such as HIV, herpes simplex, chlamydia or gonorrhea.
  • Risk of infection after gynecologic surgery: Bacterial vaginosis can lead to the development of post-surgical infections after procedures like hysterectomy or dilation and curettage.
  • Pelvic inflammatory disease (PID): Bacterial vaginosis can also cause PID, which is an infection of the uterus and the fallopian tubes that increases the risk of infertility.


It is common for bacterial vaginosis to recur within 3 to 12 months after initial treatment. It may be helpful to attempt lactobacillus colonization therapy, which aims to increase the number of good bacteria in the vagina by ingesting certain foods that contain lactobacilli in order to re-establish a natural balance in the vaginal environment.


The following steps may help prevent bacterial vaginosis:

  • Minimizing vaginal irritation: Vaginal irritation can be reduced to a minimal by avoiding hot tubs, scented soaps, tampons or pads. The genital area should also be dried well after showers
  • Avoiding douching: Frequent douching can disrupt the natural balance in the vagina and increase the risk of bacterial vaginosis.
  • Avoiding sexually transmitted infections: The risk of sexually transmitted infections can be reduced by practicing safe sex, limiting the number of sexual partners or abstaining from sex.