Gray hair at a young age is usually caused by heredity, nutritional deficiencies, illness, and mental health. 1. Heredity: People who have a genetic predisposition to gray hair in their family will be affected by their genes, and usually have a higher chance of growing gray hair at a young age. 2. Nutritional deficiencies: If the body is deficient in B vitamins, the melanin in the human body lacks the supply of nutrients, and is unable to provide the melanin needed by the hair, which may result in the development of gray hair at a young age. 3. Disease: Suffering from hyperthyroidism, cardiovascular, endocrine, neurological and other diseases, may cause young long white hair, and if you have vitiligo, will also occur local long white hair. 4. mental: if long-term late night, stress, tension, anxiety, depression and other bad mental emotions, may lead to young long white hair situation. Young long white hair is recommended to timely consultation and examination, under the guidance of the doctor to clarify the cause of the disease, in order to take corresponding treatment measures, can not be privately dealt with, so as not to cause adverse conditions.