Chronic renal failure is divided into the following stages: 1. Stage 1: renal reserve capacity compensation period, although the loss of renal reserve capacity, but can still maintain the stability of the body’s internal environment; 2. Stage 2: azotemia period, renal reserve capacity loss compensation period, patients appear mild clinical manifestations such as polyuria, increased nocturia, mild anemia and other symptoms; 3. Stage 3: renal failure period, patients appear obvious clinical manifestations such as metabolic acidosis, severe anemia, metabolic disorders, hypocalcemia, hyperphosphatemia, etc.; 4. Stage 4: uremic phase, the above renal failure symptoms are more obvious, the body appears multi-system damage.