Estimated GFR (eGFR)
The estimated glomerular filtration rate (eGFR) calculates how much blood your kidneys filter per minute, based on serum creatinine, age, sex, and sometimes race. It is the most widely used measure of kidney function and is used to stage chronic kidney disease (CKD). Unlike creatinine alone, eGFR accounts for body size and demographics.
Reference Ranges
Male
90 – 120
mL/min/1.73m²
Female
90 – 120
mL/min/1.73m²
Child
90 – 120
mL/min/1.73m²
Varies by age
Reference ranges may vary by laboratory. Always compare with the range printed on your lab report.
What Low Levels Mean
eGFR below 90 may indicate mild kidney impairment. Below 60 for 3+ months defines chronic kidney disease. Below 15 is kidney failure, potentially requiring dialysis or transplant. Stages: 60–89 (mild), 30–59 (moderate), 15–29 (severe), <15 (failure).
What High Levels Mean
eGFR above 120 is generally normal and indicates healthy kidneys. In early diabetes, eGFR can be elevated (hyperfiltration) — the kidneys work overtime. This paradoxically accelerates kidney damage over time if diabetes is not controlled.
Frequently Asked Questions
What do the CKD stages mean?
Stage 1 (eGFR ≥90 with kidney damage markers): normal filtration but some damage. Stage 2 (60–89): mildly decreased. Stage 3a (45–59): mild-to-moderate decrease. Stage 3b (30–44): moderate-to-severe. Stage 4 (15–29): severe. Stage 5 (<15): kidney failure.
Can eGFR improve?
In acute kidney injury, eGFR often recovers fully. In chronic kidney disease, eGFR decline can be slowed or stabilized by controlling blood pressure, managing diabetes, avoiding nephrotoxic drugs (NSAIDs), and reducing protein intake. Reversal of chronic damage is rare but possible in early stages.
Is eGFR accurate for everyone?
eGFR can be less accurate in very muscular people, amputees, extremely obese or underweight individuals, and during pregnancy. Cystatin C, a different blood marker, can be used as an alternative in these cases.
This information is for educational purposes only and should not replace professional medical advice. Always consult your doctor for interpretation of your test results.
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