Chronic renal insufficiency is staged according to the chronic kidney disease staging of the guidelines developed by K/DOQI, based on glomerular filtration rate (GFR), chronic kidney disease is categorized into stages 1 to 5, which can be divided into stage 1, stage 2, stage 3a, stage 3b, stage 4 and stage 5. Stage 1: Normal or elevated GFR, GFR ≥ 90 ml/(min-1.73m²). Stage 2: mildly decreased GFR, 60 to 89 ml/(min-1.73m²). Stage 3a: mild to moderate decrease in GFR, 45 to 59 ml/(min-1.73m²). Stage 3b: moderate to severe reduction in GFR, 30 to 44 ml/(min-1.73m²). Stage 4: Severe reduction in GFR, 15 to 29 ml/(min-1.73m²). Stage 5: End-stage renal disease, <15ml/(min-1.73m²) or dialysis. Therefore, if you find abnormal glomerular filtration rate, it is recommended to visit the hospital in time to get a clear diagnosis and follow the doctor's instructions for standardized treatment.