Glomerular Filtration Rate (GFR)

Overview

Glomerular filtration is the process by which the kidneys filter the blood, removing excess wastes and fluids. The estimated glomerular filtration rate (eGFR) is a calculation that determines how well the blood is filtered by the kidneys. This is one way to measure kidney function. The eGFR is also used to find the stage of chronic kidney disease.

The eGFR is often calculated using a formula that compares a person's size, age, and sex to serum creatinine levels. An eGFR under 60 mL/min/1.73 m² may mean kidney disease—the lower the eGFR number, the worse the kidney function. This number is an estimate. It may not be a good measure of kidney health in some people, such as the very young or very old, amputees, or obese people.