CKD is classified into five stages based on the GFR:
Stage 1: Normal or high GFR (≥90 mL/min) Stage 2: Mildly decreased GFR (60-89 mL/min) Stage 3: Moderately decreased GFR (30-59 mL/min) Stage 4: Severely decreased GFR (15-29 mL/min) Stage 5: Kidney failure (GFR
