Serum Creatinine with Glomerular Filtration Rate (eGFR) Calculation

What Does This Test Measure?

The test first checks your serum creatinine level, a waste product from muscle metabolism that your kidneys normally remove from your blood. Creatinine levels can vary based on muscle mass, so the eGFR calculation adjusts for this to provide a more accurate measure of kidney function.

Your eGFR helps doctors monitor kidney health over time, detect early signs of kidney disease, and guide treatment decisions for conditions like diabetes or high blood pressure.

The eGFR combines your creatinine level with other factors (like age, sex, and race) to estimate how well your kidneys are filtering blood, expressed in milliliters per minute (mL/min).

A small blood sample is drawn from a vein in your arm. The sample is sent to a lab where creatinine is measured, and the eGFR is calculated using a standardized formula.

Low eGFR may indicate kidney damage, dehydration, or conditions like heart disease or diabetes. High creatinine levels (without a high eGFR) could suggest muscle disorders or severe dehydration.

Your doctor may recommend this test periodically if you have risk factors for kidney problems, such as high blood pressure, diabetes, or a family history of kidney disease.

This test is typically ordered every 6–12 months for stable patients, or more frequently if your health status changes.