What makes hair grow white?

White hair - no one knows exactly what makes hair go white. Malnutrition or severe illness or shock have resulted in white hair, sometimes within a few days or weeks. But hair "turning white overnight" has never been authenticated. Heredity plays an important part. You can see people in their 20s who have white hairs mixed with their normal hair. It is usually traceable to parents or grandparents who have had a similar pattern of hair colour change. The hair in these cases is usually coarse or medium coarse in texture. Old age is the most frequent cause. As we grow older, many parts of the body economize and slow down. In the case of hair, the matrix or middle layer of the hair root "bulb" ceases to produce the colour granules which are normally distributed throughout the hair cells. The colour of hair is produced by the amount and proportion of pigments within it. Dark brown hair contains a lot of black brown and some red. Ash blood hair will have small amounts of black and some yellow.