Going gray might happen because the stem cells that keep your hair colored aren't working properly as you age.

Going gray might happen because the stem cells that give rise to hair color cells get damaged over time, not because the color-making cells themselves stop working. Keeping these stem cells healthy could be key to keeping your hair colored as you age.

Going gray might happen because the stem cells that keep your hair colored stop working properly as you age, according to studies in people and specially tagged mice.

Your hair color comes from cells in your hair roots, and as you age, those cells slow down — that's why hair turns gray. But new research says things like stress might also play a role.

As we age, the stem cells that give color to our hair can start acting up — they might turn into pigment cells too soon or in the wrong place, which could be why our hair turns gray.

Stress can turn your hair gray by messing with nerve signals in your hair follicles, which damages the cells that give hair its color — and once they're gone, the graying is permanent.