Hair loss, hair loss will lose 50 ~ 75 hairs every day. This is because the growth of hair is periodic and can be divided into growth period, regression period and rest period. Hair in the growing period accounts for about 85% of all hair, during which the hair grows by 0.27 ~ 0.4 mm every day. The growth period of hair is 2 ~ 6 years. After entering the regression stage, the hair bulb at the lower part of the hair follicle, including the germinal part, began to shrink. Hair no longer grows, becomes loose and easily falls off; About 1% of the hair is in a degenerative state. At rest, the lower part of the hair follicle is completely atrophied and the hair falls off, and the hair at rest accounts for about14%; The dormancy period lasts for 3~6 months, then the hair follicle enters the growth period and new hair grows again.