What is BV? BV vs yeast vs trichomoniasis

Vaginal symptoms have several common causes that look alike but are treated differently.

Bacterial vaginosis (BV)

BV happens when the balance of vaginal bacteria shifts, with fewer protective Lactobacillus. Typical signs: thin gray or white discharge and a fishy odor, usually with little itching. Many people have no symptoms. It is treated with prescription antibiotics. (CDC: About BV)

Vaginal yeast infection

Caused by overgrowth of Candida. Typical signs: itching, burning, thick white clumpy discharge without strong odor. Antifungal treatment is available over the counter and by prescription. (CDC: Vaginal candidiasis)

Trichomoniasis

An STI caused by a parasite. May cause frothy yellow-green discharge, odor, itching, and burning with urination. Needs prescription treatment, and partners should be treated. (CDC: Trichomoniasis)

Why BV recurs

Recurrence is common; studies show many people have BV return within 3 to 12 months. See prevention and treatment. The ACOG vaginitis FAQ is a good patient resource.

Not sure which applies? Use the symptom checker and read is it contagious?

Last reviewed: October 25, 2026

Medical disclaimer: This site is for education only and is not medical advice, diagnosis, or treatment. See our full disclaimer. If you have severe pain, fever, sores, or are pregnant, contact a clinician.