The causes of gray hair include physiological factors, genetic factors, disease factors, mental factors, other factors and so on. 1. Physiological factors: the elderly gray hair is physiological gray hair, with the growth of age in the black cells of tyrosinase activity disappears resulting in the loss of hair pigmentation. 2. genetic factors: such as progeria, albinism and so on. 3. Disease factors, such as vitiligo, pernicious anemia, tuberculosis and many other systemic diseases may lead to gray hair. 4. Mental factors: for example, fear and sadness, mood swings, emotional tension and other mental and psychological factors may lead to gray hair. 5. Other factors: for example, malnutrition, radionuclide irradiation and other environmental factors may cause gray hair. People with gray hair need to go to a regular medical institution to get a clear diagnosis, for the cause of gray hair treatment, patients to avoid blindly use their own medication, so as not to cause adverse consequences.