Bacterial Vaginosis Symptoms: How to Recognize BV and What to Do

What does BV feel like?

The hallmark of BV is a fishy-smelling vaginal odor, often accompanied by a thin, grayish-white discharge. The odor is frequently strongest after sex or after washing with soap, which temporarily shifts vaginal pH. Unlike a yeast infection, BV discharge is watery and thin — not thick or clumpy. Some people notice mild vaginal burning or irritation, particularly during urination or intercourse [1, 2].

Importantly, up to half of people with BV have no symptoms at all — the condition may be found incidentally during a routine pelvic exam 1Ref 1American College of Obstetricians and Gynecologists (2020).Vaginitis in Nonpregnant Patients: ACOG Practice Bulletin, Number 215.BV clinical features (thin gray-white discharge, fishy odor, asymptomatic presentation), Amsel diagnostic criteria (pH, clue cells, whiff test, discharge), antibiotic treatment, recurrence management, and BV in pregnancy.

How does BV differ from a yeast infection?

BV and yeast infections (vaginal candidiasis) are the two most common vaginal infections, and they feel quite different:

Trichomoniasis — a sexually transmitted infection — can look similar to BV and can only be reliably distinguished by lab testing. Because these infections require different treatments, self-diagnosis is unreliable. Testing by a clinician is the only way to be certain [1, 2].

Why does BV happen?

The vagina is normally home to a community of beneficial bacteria — primarily Lactobacillus species — that maintain a protective acidic environment (pH below 4.5). BV occurs when this balance shifts: the Lactobacillus population decreases and other bacteria (such as Gardnerella and Prevotella species) overgrow. What tips this balance is not fully understood 1Ref 1American College of Obstetricians and Gynecologists (2020).Vaginitis in Nonpregnant Patients: ACOG Practice Bulletin, Number 215.BV clinical features (thin gray-white discharge, fishy odor, asymptomatic presentation), Amsel diagnostic criteria (pH, clue cells, whiff test, discharge), antibiotic treatment, recurrence management, and BV in pregnancy.

Known associations include: - New or multiple sexual partners - Vaginal douching (a known risk factor; not recommended) - Products that alter vaginal pH

BV is not caused by poor hygiene, and the vagina does not need to be cleaned internally. It also occurs in people who are not sexually active [1, 2]. A diagnosis of BV does not necessarily indicate an STI .

Why does treatment matter?

BV requires prescription antibiotic treatment — typically oral metronidazole, vaginal metronidazole gel, or vaginal clindamycin cream. A full course is important even if symptoms improve before it is finished 2Ref 2Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, Reno H, Zenilman JM, Bolan GA (2021).Sexually Transmitted Infections Treatment Guidelines, 2021.BV treatment guidelines (metronidazole, clindamycin regimens), BV and STI co-occurrence, BV as risk factor for STI acquisition including HIV, douching as risk factor. Untreated BV:

• Increases susceptibility to certain sexually transmitted infections, including HIV and herpes simplex virus 2Ref 2Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, Reno H, Zenilman JM, Bolan GA (2021).Sexually Transmitted Infections Treatment Guidelines, 2021.BV treatment guidelines (metronidazole, clindamycin regimens), BV and STI co-occurrence, BV as risk factor for STI acquisition including HIV, douching as risk factor
• During pregnancy, is associated with preterm labor — making prompt evaluation and treatment particularly important for pregnant people 1Ref 1American College of Obstetricians and Gynecologists (2020).Vaginitis in Nonpregnant Patients: ACOG Practice Bulletin, Number 215.BV clinical features (thin gray-white discharge, fishy odor, asymptomatic presentation), Amsel diagnostic criteria (pH, clue cells, whiff test, discharge), antibiotic treatment, recurrence management, and BV in pregnancy

BV can recur after treatment. If symptoms return, returning to a clinician for re-evaluation — rather than re-treating without guidance — is the safer approach. For people with three or more episodes per year, a clinician may recommend a longer or maintenance antibiotic course 1Ref 1American College of Obstetricians and Gynecologists (2020).Vaginitis in Nonpregnant Patients: ACOG Practice Bulletin, Number 215.BV clinical features (thin gray-white discharge, fishy odor, asymptomatic presentation), Amsel diagnostic criteria (pH, clue cells, whiff test, discharge), antibiotic treatment, recurrence management, and BV in pregnancy.

How is BV diagnosed?

A clinician can typically diagnose BV quickly in the office using Amsel criteria — at least three of the following four findings [1, 2]:

• Vaginal pH above 4.5: BV raises vaginal pH above the normal acidic range
• Thin homogeneous discharge: the characteristic gray-white watery discharge
• Wet mount microscopy: a swab examined under a microscope identifies 'clue cells' — cells coated in bacteria that are diagnostic of BV
• Whiff test: adding a solution to the discharge sample produces the characteristic fishy amine odor if BV is present

STI testing (for chlamydia, gonorrhea, and trichomoniasis) is often done at the same visit because BV symptoms overlap with STIs and both can coexist 2Ref 2Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, Reno H, Zenilman JM, Bolan GA (2021).Sexually Transmitted Infections Treatment Guidelines, 2021.BV treatment guidelines (metronidazole, clindamycin regimens), BV and STI co-occurrence, BV as risk factor for STI acquisition including HIV, douching as risk factor.