References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Bacterial vaginosis (BV) is a very common vaginal condition caused by an imbalance in the normal bacteria. The healthy lactobacilli are reduced and other bacteria overgrow, causing a characteristic fishy-smelling discharge. BV is not officially an STI, but it’s associated with sexual activity. It’s easily treated with antibiotics.
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Symptoms
- Thin, greyish-white discharge
- Fishy odour, often worse after sex
- Usually no itching
- Many women have no symptoms
Causes
| Risk Factor | Detail |
|---|---|
| New or multiple sexual partners | Disrupts vaginal flora |
| Douching | Washes away healthy bacteria |
| Scented products | Irritates and disrupts balance |
| IUD use | Slightly higher risk |
| Antibiotics | Can disrupt balance |
Is BV an STI?
Not officially — BV is a bacterial imbalance, not a specific infection transmitted between people. However, it’s more common in sexually active women and may transfer between female partners.
Treatment
- Metronidazole (oral or vaginal)
- Clindamycin cream (alternative)
- Avoid alcohol during metronidazole treatment
- Male partners don’t usually need treatment
- Female partners may benefit from treatment if BV recurs
Prevention
- Avoid douching
- Use plain water for washing externally
- Avoid scented products and feminine washes
- Wear cotton underwear
Recurrence
BV commonly recurs — up to half of women have another episode within 12 months. Long-term management may involve suppressive treatment or probiotics, though evidence for probiotics is limited.
Read more: BV testing | BV and HIV | Yeast infection smell
Frequently Asked Questions
Will BV go away on its own?
Sometimes, but treatment is quicker and more reliable.
Can my male partner give me BV?
Not directly — BV isn’t transmitted by men in the usual way.
Is BV serious?
Usually not, but it’s linked to increased HIV susceptibility and pregnancy complications.
Related reading
- What Is a Female (Internal) Condom?
- What Is Trichomonal Vaginitis?
- Can You Test for STIs While on Your Period?
- Does a Vaginal Yeast Infection Smell?
- How Different STIs Affect Vaginal Discharge
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
