Hair breakage belongs to nodular brittle disease, common causes include genetic factors, disease factors, physical or chemical factors and other related. 1. Genetic factors: some people believe that this disease is also related to genetic metabolic diseases, especially arginine succinate enzyme deficiency, urinary arginine succinate increase in patients prone to nodular brittle disease. 2. Disease factors: certain diseases, such as ringworm, malnutrition, itchy skin disease, mental illness, etc., prone to symptoms of hair breakage. 3. Physical or chemical factors: due to the developmental defects of the hair shaft, the hair nodules or breakage can be caused by certain stimulating factors, such as perming, hair coloring, bleaching, irritating chemical stimulation, prolonged ultraviolet irradiation, or inappropriate combing and so on. It is recommended that patients according to their own situation, to the regular hospital dermatology consultation, follow the doctor’s instructions to clarify the cause of the disease, standardized scientific treatment.