Glomerular filtration rate Detail

eGFR (Estimated Glomerular Filtration Rate) is a laboratory measurement used to assess kidney function.

Description

eGFR estimates how well the kidneys are filtering blood, specifically the glomeruli, which are the tiny filtering units in the kidneys. It is calculated from serum creatinine, along with factors such as age, sex, and sometimes race.

Unlike serum creatinine alone, eGFR provides a more accurate measure of kidney filtration capacity and helps detect early kidney disease, even when creatinine levels are still normal.

Clinical Significance

• Low eGFR indicates reduced kidney function or chronic kidney disease (CKD). The stages of CKD are often classified based on eGFR:

  • Stage 1: ≥90 mL/min/1.73 m² (normal or high)

  • Stage 2: 60–89 mL/min/1.73 m² (mild decrease)

  • Stage 3: 30–59 mL/min/1.73 m² (moderate decrease)

  • Stage 4: 15–29 mL/min/1.73 m² (severe decrease)

  • Stage 5: <15 mL/min/1.73 m² (kidney failure)

• High eGFR is usually not clinically significant but may occur in early diabetes or high cardiac output states.

eGFR is often interpreted along with serum creatinine, BUN, and uric acid for a comprehensive assessment of kidney function.

Normal Range

• eGFR: ≥90 mL/min/1.73 m² is considered normal (varies with age).