Your hair color depends on special stem cells in your hair roots, and long-term stress from inflammation or oxidation can mess them up, making them disappear or mature too soon.

When the stem cells that give your hair its color get worn out or change too early because of stress in the cells, they stop making pigment, and your hair turns gray permanently.

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.

When your hair grows fast, it might stress the cells that give hair its color, causing them to wear out faster and turn hair gray sooner.

When mice experience sudden stress, it causes the cells that give hair its color to panic and leave their home in the hair follicle, burning out too soon and making the fur turn gray forever.

When mouse hair starts growing, pigment stem cells in the hair germ turn on color-making and branch-related genes before they divide.