eGFR (creatinine)

Estimated Glomerular Filtration Rate (eGFR, creatinine-based) is the standard measure of kidney function, estimating how well the kidneys are filtering waste from the blood. It is calculated using formulas (CKD-EPI 2021) that incorporate serum creatinine, age, and sex. Creatinine comes from muscle, so this estimate can be less precise in people with very low or very high muscle mass. Lower eGFR indicates poorer kidney function. Chronic Kidney Disease (CKD) stages are defined by eGFR levels (e.g., Stage 3 <60 mL/min/1.73m²). Maintaining eGFR ≥90 is generally considered ideal; a persistent decline below 60 suggests significant impairment and should be evaluated by a clinician.