How eGFR Works: A Simple Guide

Welcome to understanding eGFR, a crucial measure of kidney function.eGFR stands for estimated Glomerular Filtration Rate, which measures how well your kidneys filter waste from your blood.The glomeruli are tiny filtering units in your kidneys that clean your blood by removing waste products.To calculate eGFR, doctors use a simple blood test that measures creatinine levels, along with several personal factors.A normal eGFR is typically above 90 milliliters per minute per 1.73 square meters of body surface area.Lower numbers indicate reduced kidney function, which helps doctors assess kidney health.Now that we understand what eGFR measures, let's look at how it's calculated.The eGFR calculation primarily uses the MDRD formula, which takes several factors into account.The main input is creatinine, a waste product from muscle activity that healthy kidneys filter out of your blood.The formula then adjusts for personal factors that affect creatinine levels.The calculation process follows these specific steps to ensure accuracy.After measuring serum creatinine, we apply age adjustments since kidney function naturally changes with age.Gender is factored in because muscle mass and creatinine levels differ between males and females.Race coefficients are applied as studies have shown variations in muscle mass and creatinine generation.Finally, all these factors are combined to calculate the estimated GFR.This standardized calculation helps doctors accurately assess kidney function.eGFR results are grouped into five stages that help doctors assess kidney function.Regular monitoring of eGFR helps track changes in kidney function over time. Here's an example of how eGFR might be tracked over twelve months.Several factors can temporarily affect your eGFR results, which is why regular monitoring is important.These temporary factors should be considered when interpreting results, and retesting may be needed to confirm true kidney function.