What Is eGFR in a Blood Test?

eGFR stands for estimated Glomerular Filtration Rate. It measures how well your kidneys filter waste. Calculated from creatinine, age, and sex using the CKD-EPI equation.

Kidney Disease Stages

• 90+: Normal (Stage 1 if kidney damage present)
• 60–89: Mildly decreased (Stage 2)
• 45–59: Mild-moderate (Stage 3a)
• 30–44: Moderate-severe (Stage 3b)
• 15–29: Severe (Stage 4)
• Below 15: Kidney failure (Stage 5)

Causes of Low eGFR

• Diabetes — leading cause of CKD
• Hypertension — second leading cause
• Glomerulonephritis
• Polycystic kidney disease
• NSAIDs (long-term use)
• Acute kidney injury — dehydration, infection, medications

Important Notes

• A single low eGFR does not confirm CKD — must persist 3+ months
• Low muscle mass can falsely alter eGFR
• 2021 CKD-EPI equation removed race coefficient