| Stages CRD | Definitions | GFR (ml/min/1.73m2) |
| 1 | No kidney failure* | ≥90 |
| 2 | Mild renal impairment | 60 - 89 |
| 3 | Moderate renal impairment | 30 - 59 |
| 4 | Severe kidney failure | 15 - 29 |
| 5 | End-stage renal failure | <15 |