```html

Bacterial Vaginosis (Abnormal Discharge)

What is Bacterial vaginosis (abnormal discharge)?

Bacterial vaginosis (BV) is the most common vaginal infection among women of reproductive age. It occurs when the normal balance of bacteria in the vagina is disrupted, allowing an overgrowth of anaerobic (oxygen‑free) bacteria such as Gardnerella vaginalis, Prevotella, and Atopobium. The result is a thin, gray‑white discharge that may have a fishy odor, especially after sexual activity. BV is not a sexually transmitted infection (STI), but sexual activity can change the vaginal flora and increase risk.

Unlike yeast infections or trichomoniasis, BV typically does not cause itching, burning, or pain, which is why many women overlook it or assume the discharge is “normal.” However, untreated BV can lead to complications such as pelvic inflammatory disease (PID), preterm birth, and increased susceptibility to other STIs.

Sources: Mayo Clinic, CDC, WHO.

Common Causes

BV results from an imbalance rather than a single pathogen. Factors that disturb the vaginal ecosystem include:

• Antibiotic use that kills protective lactobacilli
• New or multiple sexual partners
• Inconsistent condom use
• Douching or using scented feminine hygiene products
• Smoking
• Hormonal changes (e.g., menstrual cycle, pregnancy)
• Intrauterine device (IUD) use
• High vaginal pH (above 4.5)
• Stress or poor nutrition that weakens the immune system
• Previous episodes of BV (recurrence is common)

Associated Symptoms

While many women with BV experience only discharge, other symptoms may appear:

• Thin, gray‑white or off‑white vaginal discharge
• Fishy or “bread‑like” odor, especially after sex or during menstruation
• Vaginal itching or irritation (less common than with yeast infection)
• Burning sensation during urination (if the discharge irritates the urethra)
• Feeling of vaginal “wetness” or “mucusiness” throughout the day

When to See a Doctor

Prompt medical evaluation is recommended if you notice any of the following:

• Sudden change in discharge color, consistency, or smell
• Persistent itching, burning, or pain
• Fever, chills, or abdominal/pelvic pain (possible progression to PID)
• Bleeding or spotting between periods
• Symptoms during pregnancy (BV is linked to preterm labor)
• Repeated episodes despite prior treatment
• Any concern that the discharge could be an STI

Early treatment can prevent complications and reduce the chance of recurrence.

Diagnosis

Healthcare providers use a combination of history, physical exam, and simple laboratory tests.

Clinical evaluation

• History: onset, duration, sexual activity, hygiene practices, recent antibiotics.
• Pelvic exam: visual assessment of discharge and vaginal walls.

Laboratory tests

• Amsel’s criteria (clinical): Diagnosis requires ≥3 of 4 findings:
  1. Homogeneous, thin, gray‑white discharge
  2. Positive “whiff” test (fishy odor after adding 10% KOH)
  3. Clue cells on microscopy (vaginal epithelial cells coated with bacteria)
  4. Vaginal pH >4.5
• Nugent score (lab‑based): Gram‑stained slide scored 0‑10 based on bacterial morphotypes; a score of 7–10 confirms BV.
• Optional: Nucleic acid amplification tests (NAATs) for concurrent STIs if risk factors exist.

Treatment Options

Treatment aims to eliminate the overgrowth of anaerobic bacteria and restore a healthy Lactobacillus‑dominated flora.

First‑line antibiotics

• Metronidazole 500 mg orally twice daily for 7 days (or a single 2 g dose). Equivalent vaginal gel (MetroGel® 0.75%) applied once daily for 5 days.
• Clindamycin 300 mg orally twice daily for 7 days or clindamycin cream (1%) intravaginally for 7 days.

Alcohol should be avoided for 24 hours after each metronidazole dose due to disulfiram‑like reactions.

Alternative regimens for recurrent BV

• Extended‑duration metronidazole (500 mg twice daily for 10–14 days)
• Combination therapy: oral metronidazole plus intravaginal clindamycin
• Probiotic adjuncts (Lactobacillus rhamnosus GR‑1 and L. reuteri RC‑14) taken orally for 30 days after antibiotics – evidence suggests reduced recurrence (Cochrane Review 2020).

Home and supportive care

• Avoid douching, scented soaps, and vaginal deodorants.
• Wear breathable cotton underwear and loose‑fitting clothing.
• Limit alcohol while on metronidazole.
• Maintain good genital hygiene: gentle washing with warm water only.
• Consider a probiotic supplement containing vaginal‑type Lactobacillus strains after finishing antibiotics.

Special considerations

• Pregnancy: Metronidazole and clindamycin are both safe in pregnancy (Category B). Treat promptly to lower the risk of preterm birth.
• Allergy to metronidazole: Use clindamycin or tinidazole (if available).

Prevention Tips

Because BV results from an imbalance, many lifestyle choices can help maintain a healthy vaginal environment.

• Limit douching: It disrupts lactobacilli and raises vaginal pH.
• Use condoms consistently: Reduces the transfer of semen, which can raise pH.
• Avoid scented hygiene products: Fragrances can irritate the mucosa.
• Practice good genital hygiene: Wash the external genitalia with warm water; pat dry.
• Quit smoking: Smoking is a recognized risk factor for BV.
• Choose breathable fabrics: Cotton underwear and loose clothing reduce moisture buildup.
• Take probiotics regularly: Especially strains proven to colonize the vagina (L. crispatus, L. jensenii).
• Maintain stable sexual relationships: Frequent changes in partners increase risk.
• Review antibiotic use with your doctor: Request narrow‑spectrum agents when possible.

Emergency Warning Signs

Key Takeaways

• BV is a common, non‑STI vaginal infection caused by an imbalance of normal bacteria.
• Typical presentation is a thin, gray‑white discharge with a fishy odor; itching is less common.
• Diagnosis is clinical (Amsel’s criteria) and/or microscopic (Nugent score).
• First‑line treatment is metronidazole or clindamycin, with probiotics useful for preventing recurrence.
• Maintain vaginal health by avoiding douching, using condoms, wearing breathable fabrics, and considering probiotic use.
• Seek prompt medical care for severe pain, fever, heavy bleeding, or pregnancy‑related concerns.

For personalized advice, always consult a healthcare professional. This information is not a substitute for professional diagnosis or treatment.

References: Mayo Clinic. Bacterial vaginosis. https://www.mayoclinic.org; CDC. Bacterial Vaginosis Fact Sheet. https://www.cdc.gov; WHO. Reproductive health guidelines; Cleveland Clinic. Vaginal discharge evaluation; Cochrane Review 2020 on probiotics for BV.

```