Young people grow white hair is mainly three reasons: the first is genetic factors, may be autosomal inheritance, that is, in the family will have a history of adolescent white head, in addition there are some serious diseases, such as hyperthyroidism, cardiovascular disease, tuberculosis, anemia and so on can appear white hair. The second is the lack of b vitamins, which may lead to an important cause of less gray hair. The third reason is that modern people work and live under great pressure, resulting in mental tension, emotional depression, long-term sleep deprivation, overthinking can also lead to gray hair.