eGFR stands for estimated glomerular filtration rate. It is the most common lab estimate of how well your kidneys are filtering waste from your blood — and the primary number used to stage chronic kidney disease.
eGFR is not measured directly in most routine care. It is calculated from your creatinine blood test result along with your age and sex. The result estimates how many milliliters of blood your kidneys filter per minute.
A healthy kidney filters roughly 90–120 mL per minute. As kidney function declines, this number drops — and waste products accumulate in the blood.
Doctors use eGFR to stage chronic kidney disease, follow trends over time, decide when specialist referral is needed, and determine whether medication doses should be adjusted.
These ranges show how eGFR maps to chronic kidney disease stages. Your doctor interprets these alongside urine tests, blood pressure, and symptoms.
Normal or near-normal filtering. CKD is only diagnosed at this level if there are other signs of kidney damage, such as protein in the urine or structural abnormalities.
Mildly reduced filtering. Doctors often watch trends closely, check urine protein, and monitor blood pressure. Many people at this stage feel completely normal.
Mild to moderate reduction. This is often where CKD management becomes more active — diet changes, medication review, and regular nephrology follow-up.
Moderate to severe reduction. Closer monitoring of potassium, phosphorus, and anemia becomes important. Medication doses may need adjustment.
Severely reduced filtering. Close nephrology follow-up is needed, and doctors begin discussing future options including transplant evaluation or dialysis preparation.
Kidney failure range. Symptoms like fatigue, nausea, and fluid retention are common. Treatment decisions about dialysis or transplant become critical.
A single eGFR value matters less than the trend. The key question is whether your kidney function is stable, drifting slowly, or dropping quickly. Here is what can cause short-term shifts:
Several formulas exist. Your lab report will typically note which one was used. The most common are:
The most widely used formula in the US. It uses creatinine, age, and sex. The 2021 version removed the race variable to reduce bias.
Uses a different blood marker (cystatin C) that is less affected by muscle mass. Helpful when creatinine-based eGFR might be inaccurate.
Uses both markers together for the most accurate estimate. Sometimes ordered when the creatinine-based number seems inconsistent with the clinical picture.
If your eGFR is below 60 on two or more tests taken at least 3 months apart, CKD is typically diagnosed. But the number alone does not tell the full story.
Your doctor will also look at urine albumin (protein), blood pressure, and the rate of change. Someone with a stable eGFR of 45 over several years is in a very different position than someone whose eGFR dropped from 70 to 45 in six months.
The most helpful thing you can do is track your eGFR over time so you and your care team can spot trends early and adjust treatment before significant function is lost.
When eGFR is tracked alongside blood pressure, urine protein, and medications, it becomes much easier to see what is changing and whether your treatment plan is working.
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