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What's the difference between eGFR and creatinine?
Creatinine is the raw measurement: how much of this muscle waste product is sitting in one deciliter of your blood. Higher generally means the kidneys are clearing less — but 'normal' depends on how much muscle you have, so the same creatinine means different things in different bodies.
eGFR takes that creatinine and adjusts it for your age and sex using an equation, producing an estimate of how many milliliters of blood your kidneys filter per minute. It's the number used to define CKD stages: 90+ is normal, 60–89 is mildly reduced, and below 60 for three months or more defines chronic kidney disease.
Read them together: creatinine tells you the input, eGFR tells you the interpretation. If your muscle mass is unusual — very high or very low — ask about a cystatin C test, which estimates GFR from a different, muscle-independent marker.
About the author
Swetha Raju
Columbia M.S. Candidate in Clinical Human Nutrition · AKF Certified Kidney Health Coach · NKF Medical Advisory Committee (MAC) Member · NKF peer mentor · CKD patient advocate · Published chronic disease and nutrition researcher
Swetha Raju is the founder of NephroNourish. As a published researcher and lifelong chronic disease patient, she translates renal nutrition and metabolic science into practical guidance people can actually use.
A note on scope. This article is educational and not individual medical advice. Always discuss changes with your nephrologist, dietitian, or care team.