Kidney function Cr, which reflects an indicator of the metabolic function of the kidneys, can be divided into blood creatinine value and urine creatinine value. When the kidney function is impaired, the blood creatinine value will be significantly higher. Clinically, the glomerular filtration rate can be further used to clarify the function of the kidney more accurately. When the kidney is damaged, especially in the early stage of damage, there will not be any clinical manifestation, only the glomerular filtration rate will show a decrease. When the kidney function is significantly decreased, when the residual kidney function is less than 30%, and the glomerular filtration rate is less than 30ml/min, there will be an increase of creatinine and urea nitrogen, which means the kidney is in the decompensated stage and needs active kidney preservation treatment. Clinically, the early stage can be treated by kidney preservation drugs, such as Bailing capsule, Kidney Health, drug carbon, compound alpha-keto acid, Haikun Kidney Hi capsule. Late stage by renal replacement therapy, such as hemodialysis, hemofiltration, kidney transplantation, etc.