What are the stages of Chronic Kidney Disease (CKD) according to the estimated Glomerular Filtration Rate (eGFR)?

CKD Staging According to eGFR

Chronic kidney disease is classified into five stages based on estimated glomerular filtration rate (eGFR), with Stages 1-2 requiring evidence of kidney damage (eGFR ≥60 mL/min/1.73 m²) and Stages 3-5 defined by progressively lower eGFR ranges alone (eGFR <60 mL/min/1.73 m²). 1

The Five CKD Stages

Stage 1: Kidney Damage with Normal or Increased GFR

• eGFR ≥90 mL/min/1.73 m² 1, 2
• Requires evidence of kidney damage (albuminuria, proteinuria, hematuria, or imaging abnormalities) 1, 2
• Focus on diagnosing the underlying cause and treating risk factors for progression 1

Stage 2: Kidney Damage with Mildly Decreased GFR

• eGFR 60-89 mL/min/1.73 m² 1, 3
• Also requires evidence of kidney damage 1, 3
• Emphasis on estimating disease progression and managing cardiovascular risk 1, 3

Stage 3: Moderately Decreased GFR

• eGFR 30-59 mL/min/1.73 m² 1
• Can be diagnosed by eGFR alone, with or without evidence of kidney damage 1
• Often subdivided into:
  • Stage 3a: eGFR 45-59 mL/min/1.73 m² 1, 3
  • Stage 3b: eGFR 30-44 mL/min/1.73 m² 1, 3, 4
• Focus shifts to evaluating and treating CKD complications (anemia, bone disease, hypertension) 1, 3

Stage 4: Severely Decreased GFR

• eGFR 15-29 mL/min/1.73 m² 1, 3
• Defined by eGFR alone 1
• Preparation for renal replacement therapy becomes priority 1, 3
• Nephrology referral is strongly recommended at this stage 1, 3

Stage 5: Kidney Failure

• eGFR <15 mL/min/1.73 m² or on dialysis 1, 3
• Defined by eGFR alone 1
• Renal replacement therapy (dialysis or transplantation) indicated if uremia present 1, 3

Critical Diagnostic Requirements

For Stages 1 and 2, eGFR alone is insufficient for diagnosis—you must document kidney damage through:

• Albuminuria (UACR ≥30 mg/g creatinine) 1, 2
• Glomerular hematuria 1
• Pathological abnormalities on biopsy 2
• Radiographic abnormalities 1, 2

For Stages 3-5, the eGFR criteria alone establish the diagnosis, regardless of whether kidney damage markers are present. 1, 3

Essential Clinical Considerations

Duration Requirement

• All abnormalities must persist for ≥3 months to differentiate CKD from acute kidney injury 1, 2, 3
• For albuminuria, two of three specimens collected over 3-6 months should be abnormal before confirming persistent albuminuria 1

Albuminuria Integration

• The KDIGO system recommends incorporating albuminuria staging at all eGFR levels for more comprehensive risk stratification 1
• Higher albuminuria at any eGFR stage increases risk of CKD progression, cardiovascular disease, and mortality 1

Common Pitfalls to Avoid

Do not rely on serum creatinine alone without calculating eGFR—this leads to missed diagnoses, especially in elderly patients or those with reduced muscle mass 2

Do not assume eGFR >60 mL/min/1.73 m² excludes kidney disease—Stages 1 and 2 CKD can exist with preserved eGFR if kidney damage is present 2, 5, 6

Do not confuse creatinine clearance with eGFR—creatinine clearance overestimates true GFR and should not be used for CKD staging 5

Do not dismiss age-related eGFR decline as "normal aging"—decreased eGFR in elderly patients remains an independent predictor of adverse outcomes and should be managed accordingly 3