Normal eGFR is typically ≥90 mL/min/1.73m². However, "normal" varies with age—eGFR naturally declines with aging. An eGFR of 60-89 in elderly patients may be acceptable.

GFR (actual) requires injecting a marker substance and measuring clearance—this is the gold standard but impractical. eGFR (estimated) uses blood tests and equations to approximate GFR quickly and non-invasively.

CKD-EPI 2021 (race-free) is currently recommended by KDIGO. It's more accurate than MDRD at higher GFR values. Cockcroft-Gault is used for drug dosing but requires weight.

The 2021 CKD-EPI equation removed race because race is a social (not biological) construct. The race coefficient may have led to health disparities by overestimating kidney function in Black patients.

Yes. High protein intake, creatine supplements, and certain medications can raise creatinine and lower eGFR. ACE inhibitors may initially lower eGFR but protect kidneys long-term.

Low eGFR indicates reduced kidney function. eGFR 60-89 = mild decrease. eGFR 30-59 = moderate decrease (CKD stage 3). eGFR <15 = kidney failure requiring dialysis consideration.

Annually for healthy adults over 60, diabetics, and hypertensives. More frequently (every 3-6 months) for known CKD patients or those on nephrotoxic medications.

Yes, in some cases. Controlling blood pressure and diabetes, stopping nephrotoxic drugs, treating infections, and lifestyle changes can improve or stabilize eGFR. However, significant kidney damage is often irreversible.

eGFR is normalized to body surface area (mL/min/1.73m²) for population comparison. Creatinine clearance (Cockcroft-Gault) gives mL/min absolute—better for drug dosing in individual patients.

Referral recommended for: eGFR <30, rapidly declining eGFR (>5 mL/min/year), significant proteinuria (>1g/day), unexplained hematuria, or resistant hypertension with kidney disease.