The reasons for long white hair on the top of the head are physiological factors and pathological factors (common in vitiligo, anemia, malnutrition and other diseases). 1. physiological factors:some patients due to genetic reasons, the phenomenon of white hair in the young; in addition, with age, the human body tyrosinase activity is reduced, melanin synthesis is reduced, easy to appear physiological long white hair phenomenon. 2. Pathological factors (1) vitiligo: the etiology of this disease is unknown, may be associated with autoimmune diseases, such as thyroid disease, hypoadrenocorticism, oxidative stress, melanocyte self-destruction, long-term mental stimulation and other factors, there can be a head of hair whitening, skin and mucous membranes appear white spot symptoms. (2) Anemia:This disease can be caused by blood loss, unbalanced diet, Crohn’s disease, chronic diseases and other factors, can appear skin and mucous membrane pallor, white hair on the head, dizziness and other symptoms. (3) Malnutrition:If congenital undernutrition or insufficient dietary intake, partiality, picky eating, etc., it is easy to lead to malnutrition, which can appear symptoms such as dry, brittle and thin hair, hair turning white, and poor mental state. It is recommended that patients, if they suspect pathological factors, go to a regular hospital in time to get a clear diagnosis and then actively treat the disease to avoid delays.