If your teeth don’t look as bright as they used to, you’re not alone. Yellowing is one of the most common cosmetic dental concerns—and while it’s rarely urgent, it can definitely affect your confidence. But before you reach for a random whitening kit, it’s helpful to understand what’s causing the discoloration in the first place.

Tooth discoloration isn’t always about poor hygiene. In fact, there are several reasons your teeth might be turning yellow—and different causes call for different solutions.