Why does hair turn white?

Hair whitening has many reasons, there are genetic, physical factors, and acquired various factors. I mainly acquired a white hair for example, explain the reasons: 1, malnutrition, lack of protein, vitamins and certain trace elements, will make hair whiter. 2, there are some internal diseases, such as tuberculosis, caused by nutritional deficiency, hair is also easy to turn white, or pituitary, thyroid disease, it will affect pigment cells produce melanin particles, will also cause hair to turn white. 3, there are mental overwork, nervous system diseases, such as encephalitis patients, also easy to turn white hair. 4, vitiligo, albinism patients, skin and hair will turn white. Show the hair turning white, it is recommended to the hospital to do the corresponding examination, find out the cause symptomatic treatment.