The top of the head is the highest end of the body, and the substances needed for hair growth cannot reach the top of the head to supply what it needs for growth when there is poor nutrition, so it will lead to gray hair on the top of the head. You should strengthen your nutrition and massage your scalp gently with your fingers or lightly comb the top part of your head every day to promote local blood circulation, which can reduce or disappear the gray hair. The synthesis of melanin in the hair follicles gradually decreases after middle age and cannot supply the melanin needed for the hair, so white hair will appear. Usually eat more melanin content food, such as black beans, black sesame, etc., help the synthesis of melanin, long-term persistence can improve this situation. Some skin diseases, such as vitiligo or psoriasis of the skin on the top of the head area, can also lead to the appearance of white hair, this situation requires active treatment of the original disease, the original disease is cured before the white hair on the top of the head will gradually disappear.