Your glomerular filtration rate (GFR) measures how well your kidneys filter waste from your blood each minute. It is estimated from a routine blood creatinine test and reported as eGFR (estimated GFR).

A normal eGFR is 90 or above. Lower numbers indicate reduced kidney function and determine the stage of chronic kidney disease (CKD):

  • Stage 1 (G1): eGFR ≥ 90 — normal or high, with other markers of kidney damage present
  • Stage 2 (G2): eGFR 60–89 — mildly decreased
  • Stage 3a (G3a): eGFR 45–59 — mildly to moderately decreased
  • Stage 3b (G3b): eGFR 30–44 — moderately to severely decreased
  • Stage 4 (G4): eGFR 15–29 — severely decreased
  • Stage 5 (G5): eGFR <15 — kidney failure

Ask your nephrologist at every visit what your current eGFR is and whether the trend is stable, improving, or declining. Small fluctuations from test to test are normal — the trend over months and years is what matters most.