A lot of gray hair may be caused by physiological factors or certain diseases. Gray hair caused by physiological factors is a normal phenomenon, generally do not need special treatment. If it is caused by certain diseases, you need to treat the primary disease. 1. Physiological factors: with age, after the age of 40, the function of hair follicles decreases, melanin production decreases, resulting in more and more gray hair on the head; the family’s grandparents or parents premature gray hair, by the influence of genetic factors, their children may be very early gray hair. The pressure of working and studying is too high, often working overtime and staying up late, and lack of sleep for a long time may lead to premature gray hair; usually do not pay attention to nutritional supplementation, the lack of trace elements, vitamins and amino acids will also lead to premature gray hair. You can choose hair coloring treatment. 2. Pathological factors: pathological factors are also the main reason for the appearance of white hair on the head, such as anemia, vitiligo, hyperthyroidism, pituitary gland lesions, is also the main reason for long white hair. If vitiligo occurs in the scalp area, resulting in the loss of melanin in the hair follicles, gray hair may appear. In addition to this, progeria and albinism, can also lead to the appearance of many gray hairs on the head. If the gray hair is caused by pathological factors, it is recommended to go to the hospital for relevant examinations, and also for the treatment of the primary disease.