What is a GFR (Glomerular Filtration Rate) number, and what does it mean?
GFR stands for Glomerular Filtration Rate . In simple terms, it is a mathematical estimate of how much blood your kidneys' tiny filtering units (called glomeruli ) are cleaning every single minute. Think of your GFR number almost like a performance efficiency score for your kidneys. The higher the number, the cleaner your blood is; the lower the number, the more the filters are struggling. How It Is Measured: The "eGFR" When you look at a lab report, you will usually see it listed as eGFR (the "e" stands for estimated ). Doctors don't measure the filtration rate directly because doing so is complicated and time-consuming. Instead, they draw a standard blood sample to measure creatinine (a normal waste product from daily muscle use). Because creatinine levels vary based on body size, the lab plugs your blood creatinine level, age, and biological sex into a formula to calculate your final eGFR score. The GFR Scoring Scale For most adults, the GFR scale r...