Hair white fast may be mental factors, malnutrition and other causes. 1. Mental factors: often stay up late or long-term emotional tension, stress, easy to make the nerve dysfunction, affecting the scalp tyrosinase metabolism, so that the hair melanin reduction, hair white. 2. Malnutrition: mostly seen in excessive weight loss, serious picky eaters, due to insufficient intake of micronutrients in food, resulting in melanin synthesis disorders, hair whitening. It is best to go to the dermatology department of the hospital in time to clarify the cause of the disease before treatment.