As hair loss is related to physiological factors, endocrine disorders, drugs, diseases and other factors, the normal value of dihydrotestosterone can only indicate that the patient’s endocrine is relatively stable, and can not be excepted for other reasons, so also hair loss. 1. Physiological factors: as hair will also have normal growth or shedding with the body’s metabolism, generally not more than 100 hair loss per day, is considered physiological factors. 2. Drugs: for patients using chemotherapy drugs such as paclitaxel, carboplatin, cisplatin, etc., due to the adverse reactions of the drugs, so it will also cause the patient’s hair loss. 3.Diseases: (1) ringworm: for patients with fungal infection of the scalp with ringworm, due to fungal contact with the scalp, growth and reproduction in the mouth of the hair follicle, destruction of the hair follicle, local scalp scales attached, so it will affect the normal growth of the patient’s hair and hair loss, and in severe cases, it is easy to cause permanent baldness. (2) Malnutrition: For patients who are usually picky eaters, partiality eaters or excessive weight loss patients, due to their insufficient intake of nutrients, they cannot supply the nutrients needed for hair growth, so there will be hair yellowing, shedding and other clinical manifestations. For patients who have normal dihydrotestosterone value, if there is still obvious hair loss, it is recommended that the patients go to regular hospitals for consultation and active treatment under the guidance of doctors after clarifying the cause of the disease.