The time it takes for stage 2 of chronic kidney disease to develop into stage 3 is usually difficult to determine, and is mainly closely related to the severity of the disease and the control of the disease, which may be as short as a few days or as long as several decades. Stage 2 chronic kidney disease usually refers to a glomerular filtration rate of 60-90mL/min, while stage 3 glomerular filtration rate is 30-60mL/min. Patients with severe and poorly controlled chronic kidney disease may suffer from recurrence or exacerbation of primary or secondary glomerulonephritis, hypertension, diabetes mellitus, ischemic nephropathy, etc., resulting in rapid deterioration of renal function, and some of the patients may progress from stage 2 to stage 3 within just a few days, and in severe cases, may also enter the stage of end-stage renal disease very quickly. The rate of progression of chronic kidney disease is also closely related to the control of risk factors such as blood glucose, blood pressure, urinary protein, hypoproteinemia and smoking. Patients with less severe and well-controlled chronic kidney disease usually have a slower progression of kidney function deterioration, and some may take decades to progress from stage 2 to stage 3. It is recommended that patients with chronic kidney disease should seek timely medical treatment, follow the doctor’s instructions, and actively control and stay away from risk factors to avoid further progression of the disease.