The gray hair in the middle of the head may be related to physiological factors, vitiligo, pemphigus and so on. 1. physiological factors: the human body normal aging process can appear hair white, so the head of the middle of the white hair may be the normal aging process. 2. Vitiligo: Vitiligo may be related to autoimmune system diseases, heredity, neurochemicals, etc. When vitiligo appears in the head, the phenomenon of long white hair may occur. 3. Pemphigus: belonging to the gene mutation leads to abnormal proliferation or differentiation of melanoblasts, local skin or hair pigmentation is lacking, can appear forehead central white spots and white hair. There may be other causes of white hair in the middle of the head, it is recommended to go to the hospital in time to improve the examination, and give targeted treatment after the cause of the disease is clear.