About eGFR
eGFR (estimated Glomerular Filtration Rate) calculates how many milliliters of blood your kidneys filter per minute based on your creatinine level, age, and sex. It is the single most important measure for assessing kidney health and stages chronic kidney disease (CKD) from Stage 1 (eGFR >90, mildly reduced) to Stage 5 (eGFR <15, kidney failure requiring dialysis). Because early CKD has no symptoms, monitoring eGFR — even when 'within normal range' — is critical for catching decline before it becomes irreversible.