The normal reference range for endogenous creatinine clearance in clinical practice is generally 80 to 120 ml/min. Endogenous creatinine clearance is commonly used as a substitute for glomerular filtration rate in clinical practice, and the normal reference value is generally 80 to 120 ml/min. When the result is lower than the normal value, it can reflect the damage of renal function earlier. Most of creatinine in human body is filtered out from glomerulus and not absorbed by renal tubules, endogenous creatinine clearance rate mainly refers to the endogenous creatinine in a certain volume of blood is cleared out within a unit of time of the kidney, and this result mainly reflects the filtration function of the glomerulus, which is often applied because of its advantages of high sensitivity, easy operation and less interfering factors. When abnormal endogenous creatinine clearance occurs, it is recommended to go to the hospital in time and follow the doctor’s instructions.