Gray hair is hair that has turned completely white or partially white. Gray hair is generally divided into two types: congenital gray hair and acquired gray hair. The main causes of gray hair are the following: i. Genetic factors. Some patients have a family history, indicating a certain relationship with heredity; second, mental and neurological factors. Mental tension, emotional distress, fright, insomnia, anxiety, sadness, etc. can cause gray hair; Third, poor dietary habits. Irrational diet, resulting in impaired synthesis of hair follicle melanocytes, causing gray hair; IV, environmental pollution; V. With age, natural aging and gray hair.