eGFR
Estimated glomerular filtration rate — measures how well your kidneys filter waste from the blood.
Optimal Range
> 90 mL/min (optimal) · 60-89 (mild decline)
Risk-Stratified Targets
| Population / Context | Target |
|---|---|
| Normal | > 90 mL/min/1.73m² |
| Mild decline (CKD Stage 2)Monitor annually; optimize blood pressure | 60–89 mL/min/1.73m² |
| Moderate decline (CKD Stage 3a)Nephrology referral recommended | 45–59 mL/min/1.73m² |
| Moderate-severe (CKD Stage 3b) | 30–44 mL/min/1.73m² |
| Severe (CKD Stage 4)Prepare for potential dialysis/transplant | 15–29 mL/min/1.73m² |
| Kidney failure (CKD Stage 5) | < 15 mL/min/1.73m² |
Why It Matters
Kidney function declines with age and is a powerful predictor of cardiovascular events and mortality. Early detection of declining eGFR allows intervention through blood pressure management, hydration, and medication adjustment.
Understanding eGFR
eGFR (estimated glomerular filtration rate) is a calculated measure of how efficiently your kidneys filter waste products from the blood, expressed in milliliters per minute. It is derived from serum creatinine (a muscle metabolism byproduct) using equations that account for age, sex, and race. Cystatin C-based eGFR is increasingly used as an alternative that is less affected by muscle mass and is considered more accurate in some populations.
Kidney function naturally declines with age — roughly 1 mL/min/year after age 40 — but this decline accelerates dramatically with hypertension, diabetes, obesity, chronic NSAID use, and dehydration. What makes eGFR particularly important is its role as a cardiovascular risk factor: chronic kidney disease (CKD) stages 3 and above (eGFR < 60) are associated with markedly increased risk of heart attack, stroke, and death — independent of traditional cardiovascular risk factors.
The key clinical message is that kidney function is both a vital sign and a modifiable risk factor. Maintaining adequate hydration, controlling blood pressure (the single most important intervention), managing blood sugar, avoiding nephrotoxic medications (chronic NSAIDs, excessive acetaminophen), and treating underlying conditions can significantly slow or halt eGFR decline. Because kidney damage is often silent until advanced, regular monitoring is essential.