The Glomerular Filtration Rate (GFR) is a key indicator of kidney function, representing the volume of fluid filtered by the glomeruli (tiny blood vessels in the kidneys) per unit of time. GFR is crucial for the removal of waste products, excess electrolytes, and fluids from the bloodstream, helping maintain internal balance (homeostasis) in the body. The GFR is typically calculated using serum creatinine levels, age, sex, race, and other factors in formulas such as the Modification of Diet in Renal Disease (MDRD) equation or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. A decline in GFR can indicate impaired kidney function and may be associated with various medical conditions, including chronic kidney disease (CKD), acute kidney injury (AKI), glomerulonephritis, diabetic nephropathy, and hypertension.