Gray hair is a common sign of aging. It happens when the cells in your hair follicles that produce melanin, the pigment that gives hair its color, start to die. As a result, the hair that grows out is white or gray.
There are a number of factors that can contribute to gray hair, including genetics, hormones, and lifestyle choices. For example, people who smoke are more likely to go gray prematurely than those who don't smoke.
