Am I at Risk? · Testing for CKD · Diagnostic Guidelines
Diagnosing the Stages of Chronic Kidney Disease
The National Kidney Foundation's Clinical Practice Guidelines, which were published in 2002 in the February issue of the American Journal of Kidney Diseases, recommend estimating glomerular filtration rate, or GFR, from the level of creatinine in the blood and checking for persistent protein in a patient’s urine— known as proteinuria—as the best way to diagnose early kidney damage. The widespread belief that measurement of GFR and the detection of proteinuria require a 24-hour urine collection has discouraged care providers from making these tests part of routine medical practice. Evidence cited in the guidelines indicates that the level of GFR and persistent proteinuria can be estimated just as accurately from blood and urine tests collected during a regular office visit.
After the GFR is calculated, one should be able to place themselves in one of the stages of chronic kidney disease if the disease is prevalent. Once the stage of CKD has been determined, physicians should develop their treatment plan based on the stage recommendations.
Fig. 1. Stages of Chronic Kidney Disease
| Stage | Description | GFR Calculation | Action |
| 1 | Kidney damage with normal or ↑GFR (Glomerular filtration rate) | ≥90 | Diagnosis and treatment, treatment of comorbid conditions, slowing progression and cardiovascular disease risk reduction |
| 2 | Kidney damage with mild ↓GFR | 60-89 | Estimating progression |
| 3 | Moderate ↓GFR | 30-59 | Evaluating and treating complications |
| 4 | Severe ↓GFR | 15-29 | Preparation for renal replacement therapy (RRT) |
| 5 | Kidney failure | <15 (or dialysis) | Replacement (if uremia present) |