Men 43 years old hair all white may be genetic factors, mental factors, disease factors and other reasons. 1. Genetic factors: premature aging of melanocytes in the hair follicle, so that melanin synthesis is reduced and hair is getting gray. It is caused by genetic factors and is usually familial. 2. Mental factors: long-term anxiety, depression, lack of sleep, etc., will cause spasm of blood vessels supplying hair nutrients, so that the function of melanin secretion by the pigment cells in the hair papilla and bulb is impaired, and the hair turns gray. 3. Disease factors: endocrine diseases such as pituitary gland diseases will affect the ability of pigment cells to produce pigment particles, and there will be a whitening of the hair. In addition, some chronic wasting diseases, such as tuberculosis, will cause malnutrition, lack of protein, vitamins and some trace elements (such as copper), can make hair gray. When there is a total gray hair, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, targeted treatment or therapy.