Bacterial vaginosis is the most common vaginal condition in people of reproductive age — by many estimates affecting roughly 1 in 3 women in the United States between the teenage years and menopause at any given time. Bacterial vaginosis (BV) is often confused with a yeast infection because both can produce discharge and discomfort, but the underlying cause is entirely different and so is the treatment. Recurrence is common, affecting more than half of people within a year of treatment, which is why understanding the condition matters as much as treating it. This article is general education, not medical advice, and is not a substitute for care from a qualified clinician.
What BV Is
Bacterial vaginosis is a shift in the vaginal microbiome away from protective lactobacilli (which produce hydrogen peroxide and lactic acid to keep the pH low) and toward an overgrowth of a mix of anaerobic bacteria, most notably Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, and various Mobiluncus species. The result is a higher vaginal pH and the characteristic discharge and odor. Because it involves a whole community of organisms rather than a single germ passed from person to person, BV is best understood as an imbalance of vaginal flora.
The CDC emphasizes that BV is not strictly a sexually transmitted infection, but sexual activity is a major risk factor and the bacterial profile of new sexual partners can shift the vaginal flora. Untreated BV can increase the risk of acquiring HIV and other STIs such as herpes, gonorrhea, and chlamydia, and during pregnancy it is associated with a higher risk of preterm birth and other complications.
Causes and Risk Factors
BV develops when the lactobacillus-dominated vaginal flora is disrupted. Common associations include new or multiple sexual partners, female sexual partners specifically, douching, intrauterine device use (with mixed evidence), antibiotic exposure, and hormonal changes. Smoking is associated with higher risk and lower cure rates. Black women have a higher prevalence than white or Asian women, though the reasons are multifactorial and not fully understood.
Importantly, people who have never had vaginal sex can still develop BV, which is why the “STI” framework does not fit. The condition reflects the ecology of the vaginal microbiome more than transmission of a specific pathogen. Coexistence with yeast infections is common, and people sometimes treat the wrong condition first — one reason self-diagnosis is unreliable.
Symptoms
The hallmark symptom is a thin, gray-white or off-white discharge with a strong “fishy” odor, often more noticeable after sexual intercourse or during menstruation. The odor is frequently the symptom that drives people to seek care. Vaginal pH rises above 4.5 (compared with a normal range of about 3.8 to 4.5), and lactobacilli decline.
BV does not typically cause significant itching or burning; those symptoms point more toward a yeast infection or another cause, which is a useful clue but not a substitute for testing. Notably, a large share of people with BV — by some estimates up to half or more — have no symptoms at all. Asymptomatic BV often does not require treatment unless the person is pregnant, has symptoms, or is undergoing certain gynecologic procedures; a clinician can advise on your situation.
How BV Differs from Yeast Infections and STIs
Because treatment does not overlap, distinguishing BV from other causes is essential. A yeast (candida) infection typically causes itching and a thick, white, “cottage cheese” discharge without a fishy odor, and it is treated with antifungals — not antibiotics. Trichomoniasis, a true STI, can cause frothy discharge, odor, and irritation and requires specific antibiotic treatment plus partner care. Overlapping symptoms and the fact that these conditions can coexist are exactly why accurate testing beats guessing at the pharmacy shelf.
Diagnosis
Diagnosis commonly uses the Amsel criteria (at least 3 of 4: thin homogeneous discharge; vaginal pH greater than 4.5; a positive “whiff” test with potassium hydroxide producing a fishy odor; and clue cells on microscopy) or the Nugent score (a Gram-stain-based score of 7 to 10 on a 0-to-10 scale). Both methods are accurate when performed correctly by a trained clinician or lab.
Newer DNA-based tests (such as certain panels that detect BV-associated organisms alongside yeast and trichomoniasis) are increasingly used in clinical practice. Self-diagnosis based on symptoms alone is unreliable, particularly because BV and yeast infection can coexist and produce overlapping symptoms — which is why a clinical evaluation is the right first step.
Treatment
Do not self-medicate. The regimens below are provided for general understanding of what a clinician may prescribe — they are not dosing instructions for you to follow on your own. Antibiotic choice, dose, and duration should be set by a prescriber based on your history, allergies, pregnancy status, and other factors, and you should complete the full course even if symptoms improve early.
According to the current CDC STI Treatment Guidelines, recommended (first-line) options include oral metronidazole for 7 days, intravaginal metronidazole 0.75% gel for 5 days, or intravaginal clindamycin 2% cream for 7 days. These regimens have broadly similar short-term cure rates. Alternative regimens listed by the CDC include oral clindamycin, clindamycin ovules, secnidazole (a single oral dose of granules), and tinidazole. Which one a clinician chooses depends on your circumstances, cost, and tolerance.
A few safety points your clinician will reinforce: with oral metronidazole or tinidazole, the traditional advice is to avoid alcohol during treatment (and for a short period afterward) because of a possible disulfiram-like reaction — recent evidence suggests this risk may have been overstated, but follow your prescriber’s guidance. Clindamycin cream is oil-based and can weaken latex condoms and diaphragms during and shortly after use. And no matter the regimen, finishing the full course helps reduce the chance of early recurrence.
Recurrent BV is managed more intensively and always under medical supervision. Reported strategies include suppressive intravaginal metronidazole gel used twice weekly for several months, longer or repeated courses, and adjunctive vaginal boric acid followed by suppressive gel. Boric acid is for vaginal use only and is toxic if swallowed — it must never be taken by mouth, kept away from children, and used only if a clinician recommends it. Newer approaches, including vaginal microbiome-directed and lactobacillus-based products, are being studied, with evolving evidence.
BV in Pregnancy
Symptomatic BV during pregnancy is treated to relieve symptoms and because BV is associated with a higher risk of preterm delivery, late miscarriage, and postpartum infection. Treatment during pregnancy should always be directed by your obstetric clinician, who will choose an appropriate regimen. Routine screening of asymptomatic pregnant people without a prior preterm birth is not recommended by the USPSTF, though management of higher-risk patients is individualized. If you are pregnant and notice new discharge or odor, contact your clinician rather than treating it yourself.
Prevention and Recurrence
Recurrence is the central challenge; more than half of people treated for BV experience a return within 12 months. Prevention focuses on supporting healthy vaginal flora: do not douche (douching disrupts the microbiome and is consistently discouraged), avoid unnecessary antibiotic exposure, avoid scented vaginal products, and consider condoms, which reduce the bacterial transfer that can disturb flora. Smoking cessation may also help.
Probiotics — particularly certain Lactobacillus crispatus and Lactobacillus rhamnosus strains — have modest and mixed evidence for reducing recurrence, and commercial products vary widely in quality. Boric acid suppositories used adjunctively have a long history of off-label use with reasonable safety when used vaginally under guidance. The broader women’s health conditions overview ties together the multiple approaches to vaginal health.
On partners: current CDC guidance states that routine treatment of sex partners is not recommended, because a person’s response to therapy and likelihood of recurrence have not been shown to change based on treating a partner. That said, research is evolving — a 2024 randomized trial suggested that treating male partners may reduce recurrence in some couples, prompting specialists to reconsider the question. Ask your clinician what the latest evidence means for your situation rather than acting on headlines.
When to See a Doctor
Schedule a visit if you have new or unusual vaginal discharge, a fishy odor (especially after intercourse), pelvic pain, fever, or symptoms that do not improve. New symptoms during pregnancy warrant prompt evaluation. Recurrent or refractory BV needs a more targeted approach, potentially including microscopy and molecular testing. Do not rely on over-the-counter products marketed for “feminine odor” to treat a suspected infection.
When to seek emergency care: Call 911 or go to the nearest emergency room if you experience high fever, severe pelvic pain, signs of pelvic inflammatory disease (severe pain with deep palpation, cervical motion tenderness, fever), or rapidly worsening symptoms. BV alone is rarely an emergency, but it can coexist with more serious infections such as PID, which require urgent care.
Frequently Asked Questions
Can BV go away on its own?
Sometimes mild cases resolve without treatment. However, untreated BV raises the risk of acquiring STIs and, during pregnancy, can contribute to complications. Treatment is recommended for people with symptoms and in certain other situations, so check with a clinician rather than waiting it out.
Is BV a sexually transmitted infection?
Not in the strict sense. BV is a disturbance of the vaginal microbiome, though sexual activity — especially with new or multiple partners, including female partners — is a strong risk factor. Condom use is associated with reduced recurrence in studies.
Why do I keep getting BV?
Common contributors to recurrence include douching, practices that disrupt flora, hormonal changes, smoking, and differences in the underlying vaginal microbiome. Suppressive treatment, addressing modifiable triggers, and (in some cases) adjunctive therapies can help. Ask your clinician about a recurrence-focused plan.
Can I treat BV with home remedies?
OTC and folk remedies (yogurt, garlic, vinegar douches, hydrogen peroxide rinses) lack rigorous evidence and can disrupt flora further; douching in particular is discouraged. Boric acid has some support as an adjunct, but only vaginally and under medical guidance — never by mouth. Prescriber-directed antibiotics remain the standard treatment.
This article is general education, not medical advice, and is not a substitute for care from a qualified clinician. Do not self-diagnose or self-treat vaginal symptoms — BV, yeast infections, and STIs can look alike and are treated differently. Any antibiotic must be prescribed and dosed by a clinician; take the full course as directed, follow guidance about alcohol with metronidazole, and never take boric acid by mouth. Seek prompt care if you are pregnant, have pelvic pain or fever, or your symptoms do not improve.
The Practical Takeaway
Bacterial vaginosis is common, often mistaken for a yeast infection, and frequently recurrent. Prescriber-directed antibiotic regimens cure most initial cases, but because recurrence within a year is common, prevention and microbiome-supportive practices — above all, not douching — are central to long-term management. Distinguishing BV from yeast infection or trichomoniasis is essential because the treatments do not overlap, so start with a clinical evaluation rather than the pharmacy shelf. If symptoms keep returning despite treatment, ask your clinician about testing, suppressive regimens, and adjunctive therapies, since BV management has moved well beyond a single course of antibiotics.
Sources
- CDC — STI Treatment Guidelines: Bacterial Vaginosis (recommended and alternative regimens; recurrence and partner-treatment guidance)
- CDC — Bacterial Vaginosis fact sheet
- ACOG — vaginitis / bacterial vaginosis patient information (general reference)
- MedlinePlus — Bacterial Vaginosis (general reference)
- U.S. Preventive Services Task Force (USPSTF) — screening for bacterial vaginosis in pregnancy