Whether gray hair can become black or not needs to be judged on a case-by-case basis, and cannot be generalized. If a small amount of gray hair appears in adolescent youngsters, it is mostly due to poor nutrition, or irregular daily life, often stay up late, life is too stressful and other reasons, can improve the habits of life, pay attention to diet and nutrition and ensure sufficient sleep, keep a happy mood, most patients gray hair can gradually turn black. If only a piece of hair turns white, consider it may be scalp vitiligo, need to be treated according to vitiligo disease, follow the doctor’s advice topical and oral symptomatic drugs, if necessary, ultraviolet radiation treatment to activate the damaged melanocytes in the hair follicles, so as to achieve the purpose of turning white hair into black hair. However, if it is a family genetic factor, i.e., less white head, the possibility of turning white hair into black hair is less. In addition, in the case of middle-aged and elderly people, especially if they are over 55 years old, the appearance of gray hair is a normal aging process of the body and it is difficult to turn gray hair black again. Therefore, it is recommended that patients who find their hair abnormally white need to go to the hospital dermatology department in time to identify the cause and take appropriate treatment measures.