The azotemia phase refers to a period of chronic renal failure, which is one of the older staging methods. In the previous staging chronic renal failure was divided into compensated, decompensated, azotemia, renal failure, and uremic stages. Patients in the azotemia stage look at the blood creatinine level, which requires a standard of 178-442 μmol/L, and the patient has to be in chronic renal failure. Patients generally have a small kidney volume, the dermal medullary demarcation may not be clear, and patients may have mild anemia, which is consistent with the above clinical features can be considered as chronic renal failure azotemia stage.