Hair loss is a common clinical condition that is associated with a variety of factors. Depending on the situation hair loss can be divided into the following types: 1. Periodic hair loss: 50-100 hairs shed per day is considered normal and is called physiological hair loss. Because the growth of hair is cyclical, hair in the growth phase is not easy to fall off. After the growth period, the hair is in a state where it is easy to fall out, called natural hair loss. 2, resting hair loss: resting hair is easy to fall out, when certain factors lead to too many hair follicles into the resting phase, there will be a lot of hair loss, beyond the amount of natural hair loss, such as the emergence of great mental stress, in a short period of time can be shed 1/3-1/2 of the hair, when the pressure is removed, the hair follicles will gradually return to normal, so that the resting hair follicles back to the anagen state. 3, male pattern hair loss: is the most common to male hair loss causes, related to androgen secretion, other factors including genetic factors, age, etc.. 4, hair loss due to emotional problems: mental factors such as when a person is in tension, anxiety, sebaceous glands secretion, dermoid secretion imbalance, hair follicle damage, will cause hair loss. In general, non-physiological hair loss is related to staying up late, poor lifestyle habits and mental factors.