The causes of gray hair may be related to physiological factors such as excessive mental stress and aging, or it may be caused by diseases such as albinism and vitiligo. 1. Physiological factors: with the age, the older people will appear the situation of long white hair, is a normal phenomenon. If the mental stress is too large, long-term tension and anxiety, may also trigger long gray hair. 2. albinism: its causes are mostly related to melanin production abnormalities, heredity and other factors, the patient may appear eye hypopigmentation, skin color white, hair becomes white, red, black and so on. 3. Vitiligo: it is the destruction of melanocytes that leads to the skin white spots of the disease, which occurs in the face, hands, and abdomen, etc. Vitiligo on the head and face will appear white hair. The cause of the disease is related to reduced melanin production, autoimmune system diseases, and hereditary factors. There are many reasons for long white hair, after excluding physiological factors, you should go to the hospital for examination, to clarify the cause of the disease, and follow the doctor’s instructions for treatment.