What is GFR? (Glomerular Filtration Rate)

GFR (Glomerular Filtration Rate) is a medical measurement that shows how well your kidneys are filtering blood. Your kidneys contain tiny filters called glomeruli that remove waste, toxins, and excess fluid from your body. GFR measures how much blood passes through these filters each minute. GFR is usually estimated through a blood test that checks creatinine levels. The result is shown in mL/min/1.73m². A normal GFR is typically 90 or higher, while a lower number may indicate kidney damage or chronic kidney disease. Doctors use GFR to detect kidney problems early, monitor kidney health, and determine the stage of kidney disease. In early stages, there may be no symptoms, which is why regular testing is important—especially for people with diabetes or high blood pressure.