The glomerular filtration rate of a normal adult is between 80 and 120 ml/min, and can be normal if the glomerular filtration rate of a 70-year-old is within this range. Glomerular filtration rate is the amount of plasma fluid filtered out by the glomerulus per unit of time (minute), i.e., the amount of ultrafiltrate generated by the kidneys on both sides per unit of time (minute). Glomerular filtration rate cannot be measured directly, but can only be inferred from the renal clearance or plasma clearance of some marker. However, glomerular filtration rate may also gradually decrease with age. If the glomerular filtration rate of a 70-year-old man is abnormal, it is recommended to go to a regular hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment under the guidance of the doctor.