Bacterial Vaginosis (BV)

BV happens when the vagina’s protective lactobacilli lose ground and other bacteria overgrow. It’s the most common vaginal condition there is, it isn’t caused by poor hygiene, and it isn’t classified as an STI — though sex can shift the balance. The practical problem: it’s routinely mistaken for a yeast infection and treated with the wrong thing.

What it is

A healthy vagina maintains a mildly acidic environment through lactobacilli — beneficial bacteria that keep other microbes in check. BV is what happens when that ecosystem tips: anaerobic bacteria overgrow, pH rises, and symptoms follow. It’s an imbalance, not an invasion, and having it says nothing about cleanliness — douching, in fact, makes it more likely, not less.

Signs and symptoms

The typical pattern is thin, grayish-white discharge and a distinct fishy odor, often more noticeable after sex. Itching and burning are usually mild or absent — which is one clue it isn’t yeast, where itching dominates. Up to half of BV cases cause no symptoms at all.

What you can track at home

Vaginal pH is the differentiator. BV raises pH above the normal 3.8–4.5 range; yeast infections usually leave it normal. If something feels off, a pH swab gives you a real signal: elevated pH points toward BV or another cause that needs a provider’s diagnosis, while normal pH with itching points toward yeast. That one data point prevents the most common mistake — treating BV with over-the-counter yeast medication that won’t touch it.

When to see a doctor

BV is treated with prescription antibiotics, so an elevated pH with symptoms is a reason to book, not to wait — untreated BV can raise the risk of other infections and matters in pregnancy. See a provider promptly if symptoms come with pelvic pain or fever, if you’re pregnant, or if BV keeps returning; recurrence is common and manageable with the right plan.