Hair loss is a serious performance of many factors, does not matter what the precursor of the disease, if the amount of hair loss per day in the 70 to 100, is a normal physiological phenomenon, if the amount of hair loss per day more than 100, may be androgenetic alopecia, baldness and other diseases caused. 1. Physiological factors: under normal circumstances, everyone will have a certain amount of hair loss every day, the amount of hair loss per day is not more than 100, is a normal physiological phenomenon, will not affect the health of the body, daily attention should be paid to avoid staying up all night, keep a happy mood. 2. Androgenetic alopecia: this disease has a certain genetic predisposition, but also closely related to androgen secretion, manifested as progressive hair thinning, shedding, sparse, severe hair loss, male M-shaped hair loss until the top of the hair loss, appearing “Mediterranean Sea”, women’s head of the central part of the hair gradually become thin, sparse and other symptoms. 3. Patchy baldness: the cause of this disease is not yet completely clear, and may be related to genetic, autoimmune, neuropsychiatric, infection, endocrine disorders, drugs and other factors. It manifests itself as sudden patchy hair loss, with smooth skin at the site of the hair loss patch and no rash, inflammation, scaling, scarring and other symptoms. It is recommended that patients according to their own situation, such as suspected disease, need to go to the regular hospital dermatology consultation and examination, after a clear diagnosis, under the guidance of the doctor to carry out targeted treatment, to avoid delaying the condition.