eGFR (Estimated Glomerular Filtration Rate)

What is eGFR?

eGFR stands for estimated Glomerular Filtration Rate. It measures how much blood your kidneys filter per minute, expressed in mL/min/1.73m².

Rather than being measured directly, eGFR is calculated from your creatinine level, age, sex, and sometimes race. It's the standard way doctors assess kidney function.

Think of it as a percentage of normal kidney function. An eGFR of 90 means your kidneys are working at roughly 90% capacity.

Normal Ranges

eGFR Value	Kidney Function
90+	Normal
60–89	Mildly reduced
45–59	Mild to moderate reduction
30–44	Moderate to severe reduction
15–29	Severely reduced
Below 15	Kidney failure

A single low reading doesn't necessarily indicate chronic kidney disease. Doctors typically look for sustained low values over 3+ months.

Why It Matters

Early Detection

Kidney disease often has no symptoms until significant damage has occurred. eGFR catches declining function early, when intervention is most effective.

Medication Safety

Many medications are processed by the kidneys. If your eGFR is low, certain drugs may need dose adjustments or should be avoided entirely.

Cardiovascular Connection

Reduced kidney function is strongly associated with increased cardiovascular risk. Tracking eGFR helps monitor overall health, not just kidney health.

What Affects eGFR

Several factors can temporarily affect your eGFR reading:

Hydration status — Dehydration can lower eGFR
Recent intense exercise — Can temporarily raise creatinine
High-protein meals — May affect creatinine levels
Certain medications — NSAIDs, some blood pressure drugs

How Often to Test

No risk factors: Every few years as part of routine blood work
Diabetes or hypertension: Annually
Known kidney disease: Every 3–6 months or as directed