Glomerular filtration rate (GFR) represents the flow of plasma from the glomerulus into Bowman’s space over a specified period and is the chief measure of kidney function. The kidneys receive 20% to 25% of the cardiac output (about 1.0 to 1.1 liters per minute) with the blood entering individual glomerular tufts via the afferent arteriole and exiting through the efferent arteriole. Of this renal blood flow (RBF), only the plasma can cross the structures comprising the glomerulus. Thus, the ... About estimated glomerular filtration rate (eGFR) Your kidneys filter your blood by removing waste and extra water to make urine. The best way to know how well your kidneys are filtering the blood is to look at your estimated glomerular filtration rate (eGFR). Your eGFR is calculated using your serum (blood) creatinine level, age, and sex. The MDRD GFR Equation estimates glomerular filtration rate based on creatinine and patient characteristics. eGFR Calculator Glomerular filtration rate (GFR) is the best overall index of kidney function. Normal GFR varies according to age, sex, and body size, and declines with age. The National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) convened a Task Force in 2021 to focus on the use of race when estimating GFR.
