Low inorganic phosphorus may be related to heredity, malnutrition, renal disease, endocrine disease and other reasons, which will lead to developmental delay, anorexia and other serious harms, and it is recommended that timely hospital consultation and treatment. 1.Causes (1) Genetic factors: Familial hypophosphatemia is an autosomal dominant disease, usually caused by defective genes inherited from parents. (2) Malnutrition: It will reduce the amount of phosphate absorbed by the intestines, thus leading to hypophosphatemia. (3) Kidney disease: such as Fanconi syndrome, which leads to an increased ability to excrete phosphate. (4) Endocrine diseases: such as hyperthyroidism, which leads to hypophosphatemia. 2. Hazards (1) Developmental delay: congenital hypophosphatemia will affect the child’s height, physical and intellectual development. (2) Anorexia: Hypophosphatemia will gradually affect the intestinal tract, resulting in decreased absorption and conversion ability, and is prone to anorexia. Low inorganic phosphorus is recommended to consult the hospital in time to clarify the cause of the disease and follow the doctor’s instructions for treatment.