In clinical practice, chronic renal insufficiency is divided into five stages according to the different values of endogenous creatinine clearance, CKD1 stage is relatively the lightest, with endogenous creatinine clearance greater than or equal to 90 ml/min. CKD2 stage has endogenous creatinine clearance between 60-89 ml/min, CKD3 stage is endogenous creatinine clearance between 30-59 ml/min, and CKD4 stage is endogenous creatinine clearance between 15-29 ml/min. For patients with CKD stage 5 is equivalent to end-stage renal insufficiency, that is to say, the most serious category, endogenous creatinine clearance is less than 15ml/min or less. For patients with CKD stage 5, renal replacement therapy can be started, such as hemodialysis, peritoneal dialysis or kidney transplantation.