The causes of gray hair formation may be related to physiological factors, or may be related to pathological factors. 1. Physiological factors: Commonly found in the elderly, along with ageing, the elderly body in the melanocytes in the enzyme activity of the complex gradually lost, resulting in the disappearance of the hair shaft pigmentation. Because the number of melanocytes in gray hair is normal, while melanin secretion is obviously reduced, white hair will be formed. This is a normal physiological phenomenon, without special intervention. 2. Pathological factors: (1) Psychological factors: If you suddenly encounter some stressful events, such as the sudden death of a friend or relative, or a sudden loss of career, leading to excessive anxiety, sadness and fear, which can lead to serious psychosomatic disorders, it will make the melanocyte dysfunction of the hair and the appearance of gray hair. (2) Disease factors: can be seen in some skin diseases, such as vitiligo, etc., the cause of the disease is not yet clear, is a variety of reasons for the lack of melanocytes; can also be seen in internal diseases, such as tuberculosis, malignant tumors, etc., these diseases may lead to lack of nutrients in the body, resulting in the formation of white hair; can also be seen in hereditary diseases, such as albinism, progeria, and so on. White hair may also be caused by other reasons, if accompanied by other obvious symptoms, it is recommended to consult a doctor as soon as possible, after a clear diagnosis of the cause, to give targeted treatment.