The normal value of glomerular filtration rate is usually 80~120ml/min, due to the influence of age, the glomerular filtration rate of elderly people over 80 years old usually decreases, the specific range needs to be based on the age, and cannot be generalized. Glomerular filtration rate is affected by age, with age, the glomerular filtration rate decreases, usually after 40 years old, the decline is about 10% every 10 years, the specific varies from person to person. Therefore, glomerular filtration rate usually decreases in people over 80 years old, and the exact range depends on age. If you have a low glomerular filtration rate or other discomforts such as edema, foamy urine, etc., it is recommended that you go to the hospital to find out the cause of the problem and take standardized treatment under the guidance of the doctor to avoid the progression of the disease.