Bacterial Vaginosis

A common imbalance of vaginal bacteria causing a thin, fishy-smelling discharge.

Women's healthInfectionLast updated: 21 October 2026

Quick Summary

Primary Symptoms

Thin grey or white discharge with a fishy smell, especially after sex. Often no itching.

Common Treatments

Antibiotics such as metronidazole tablets or gel.

Risk Factors

Douching, new or multiple sexual partners, and using scented products.

OverviewSymptomsCausesTreatmentFAQ

Overview

Bacterial vaginosis (BV) happens when the normal balance of bacteria in the vagina changes.

It isn't a sexually transmitted infection, but it's linked to sexual activity. In pregnancy it should be treated.

Symptoms

Discharge

Thin, grey or white.

Fishy smell

Stronger after sex.

Often no symptoms

In about half of women.

Mild irritation

Sometimes.

Causes & Risk Factors

Biological Causes

Overgrowth of certain bacteria and fewer protective lactobacilli.

Key Risk Factors

  • Douching Upsets the natural balance.
  • Sexual activity New partners.
  • Scented products Soaps and washes.

Management & Treatment

01. Antibiotics

Metronidazole tablets or gel.

02. Avoid douching

And scented products.

03. Recurrent BV

Longer treatment may be needed.

Frequently Asked Questions

Is BV dangerous?
Usually not, but it raises the risk of some infections and pregnancy problems.
Should my partner be treated?
Male partners usually don't need treatment.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.