Definition and stages of chronic kidney disease based on kidney disease outcomes quality initiatives (K/DOQI) guidelines51
| Stage | Description | GFR (ml/min/1.73 m2) |
| I | Kidney damage with normal or increased GFR | ≥90 |
| II | Kidney damage with mildly decreased GFR | 60–89 |
| III | Moderately decreased GFR | 30–59 |
| IV | Severely decreased GFR | 15–29 |
| V | Kidney failure | <15 (or dialysis) |
Chronic kidney disease is defined as either kidney damage or glomerular filtration rate (GFR) <60 ml/min/1.73 m2 for >3 months. Kidney damage is defined as pathological abnormalities or markers of damage including abnormalities in blood or urine tests or imaging studies.