The Glomerular Filtration Rate (GFR) is a measure of how well the kidneys filter blood. It indicates the volume of blood that passes through the glomeruli, tiny structures in the kidneys, each minute. A normal GFR is essential for maintaining the body's balance of fluids and electrolytes. GFR is often estimated using blood tests that measure levels of creatinine, a waste product produced by muscles. A low GFR can signal kidney dysfunction or disease, while a high GFR may indicate conditions like diabetes or hypertension. Regular monitoring of GFR helps assess kidney health and function.