Chronic kidney disease stage 1 is less serious because chronic kidney disease is defined as: 1. Structural and functional abnormalities of the kidney, greater than or equal to 3 months, including the presence of albuminuria ≥ 30 mg and urinary albumin to urinary creatinine ratio ≥ 30 mg/mmol. Urinary sediment abnormalities with red blood cells and tubular pattern, decreased glomerular filtration rate and impaired tubular function, and abnormal changes in renal echogenicity on imaging. 2. Decreased GFR, less than 60mL/min, greater than 3 months with or without evidence of renal injury. Chronic kidney disease stage 1 with normal renal function, i.e. normal blood creatinine and urea nitrogen, normal renal tubular function, no clinical symptoms and creatinine clearance ≥ 90mL/min, has a better prognosis as long as the focus is on renal protection and regular review.