In renal insufficiency, according to the grading of blood creatinine, chronic renal insufficiency can be divided into compensated phase of chronic renal failure, decompensated phase of chronic renal failure, renal failure phase of chronic renal failure and uremic phase of chronic renal failure, where the decompensated phase of chronic renal failure is also called the azotemia phase of chronic renal failure. The specific creatinine classification is the compensated phase of chronic renal failure, which refers to creatinine between 133-177umol/L, the decompensated phase of chronic renal failure, which refers to creatinine between 178-442umol/L, the renal failure phase of chronic renal failure, which refers to creatinine between 443-707umol/L, and the uremic phase, which refers to creatinine greater than 707umol/L. This classification is older and is no longer used for classification in this way, choosing instead to classify chronic kidney disease into five stages based on endogenous creatinine clearance.