Bacterial Vaginosis
Also known as: BV, Vaginal bacteriosis
Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in women of reproductive age. It happens when the protective Lactobacillus bacteria that normally dominate the vagina are replaced by an overgrowth of other bacteria, raising the vaginal pH. The hallmark is a thin, grayish-white discharge with a fishy odor that is often stronger after sex. BV is not classed as a sexually transmitted infection, though sexual activity influences it. It is easily treated with antibiotics but frequently returns. Treating it matters because untreated BV increases the risk of acquiring sexually transmitted infections and of complications in pregnancy.
At a Glance
- Common symptoms
- Thin, watery, gray or white vaginal discharge, A fishy odor, often more noticeable after sex or during periods, Mild itching or irritation (less intense than with yeast)
- Main treatments
- Oral metronidazole for several days (avoid alcohol during and shortly after treatment), Metronidazole or clindamycin vaginal gel or cream, Alternative antibiotics such as tinidazole or secnidazole in some cases
- Category
- Reproductive · Very common; the leading cause of vaginal discharge in women of reproductive age
- See a doctor if
- New vaginal discharge with an odor, especially if you have never had it diagnosed
Symptoms
Causes
- Disruption of the normal vaginal bacterial balance
- Overgrowth of anaerobic bacteria such as Gardnerella vaginalis
- Loss of hydrogen-peroxide-producing Lactobacillus species
- Douching, which washes away protective bacteria
- Changes linked to new or multiple sexual partners
Risk Factors
- Douching or using scented washes
- A new sexual partner or multiple partners
- Not using condoms
- Having a copper IUD
- Smoking
- Naturally low levels of Lactobacillus
Diagnosis
- Review of symptoms and sexual and hygiene history
- Pelvic examination to observe the discharge
- Vaginal pH test (BV typically raises it above 4.5)
- Microscopy of a vaginal swab looking for 'clue cells', or a laboratory test
- Screening for sexually transmitted infections when appropriate
Treatment
- Oral metronidazole for several days (avoid alcohol during and shortly after treatment)
- Metronidazole or clindamycin vaginal gel or cream
- Alternative antibiotics such as tinidazole or secnidazole in some cases
- Longer suppressive courses for frequent recurrences
- Supportive: stopping douching and scented products to let normal bacteria recover
- Supportive: consistent condom use, which is associated with fewer recurrences
- Supportive: some evidence suggests certain Lactobacillus probiotics may help prevent recurrence after antibiotics, though results are inconsistent
Prevention
- Do not douche
- Use mild, unscented soap externally only
- Use condoms, particularly with new partners
- Limit the number of sexual partners
- Stop smoking
When to See a Doctor
- New vaginal discharge with an odor, especially if you have never had it diagnosed
- Symptoms persist or return after completing treatment
- You are pregnant and notice abnormal discharge
- Discharge comes with fever, pelvic pain, or pain during sex
- You have had a new partner and could be at risk of a sexually transmitted infection
Frequently Asked Questions
Related Conditions
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