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CKD Stage (KDIGO)

KDIGO Staging

CGA Risk Stratification

KDIGO recommends testing both GFR and Albuminuria.

Stage Manifest

Enter eGFR to determine KDIGO Staging and monitoring protocols.

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Definition of CKD

Chronic Kidney Disease (CKD) is defined as abnormalities of kidney structure or function, present for > 3 months, with implications for health.

When to Use

Staging patients with established kidney damage (e.g., albuminuria, structural abnormalities).
Risk stratification for progression to End-Stage Renal Disease (ESRD).
Determining the frequency of monitoring and necessity for nephrology referral.
Guidance for cardiovascular risk management and drug dosing.

Diagnostic Requirements

GFR < 60 mL/min/1.73 m2 (G3a–G5) confirmed for > 3 months.
OR markers of kidney damage (e.g., ACR ≥ 30 mg/g, hematuria, structural changes) for > 3 months.

How it Works

CGA Classification (2012 KDIGO)

Modern staging uses the CGA triad: Cause (if known), GFR category (G1-G5), and Albuminuria category (A1-A3).

G-Stage: GFR Categories

G1≥ 90 mL/min (Normal/High)
G260–89 mL/min (Mildly decreased)
G3a45–59 mL/min (Mild-Moderate)
G3b30–44 mL/min (Moderate-Severe)
G415–29 mL/min (Severely decreased)
G5< 15 mL/min (Kidney failure)

A-Stage: Albuminuria Categories

A1 (Normal)ACR < 30 mg/g (< 3 mg/mmol)
A2 (Moderate)ACR 30–300 mg/g (3–30 mg/mmol)
A3 (Severe)ACR > 300 mg/g (> 30 mg/mmol)

Clinical Pearls

The Importance of Albuminuria

Albuminuria is an independent predictor of mortality and ESRD. A patient with GFR 65 (G2) and ACR > 300 (A3) has a higher risk of death than a patient with GFR 45 (G3a) and ACR < 30 (A1).

Staging Pearls

Stages G1 and G2 ONLY qualify as CKD if there is evidence of kidney damage (A2/A3, hematuria, or imaging findings).
Always use the CKD-EPI equation for staging; it is more accurate than MDRD at higher GFR levels.
In patients with AKI, GFR estimates are unreliable; wait for steady-state creatinine for staging.

The "Race-Neutral" Shift

The 2021 CKD-EPI equation has removed the race coefficient. Ensure your laboratory is using the 2021 race-independent formula to avoid systematic overestimation of kidney function in Black patients.

Next Steps

Monitoring Frequency (per year)

Green (Low Risk)1x per year
Yellow (Moderate Risk)1x per year
Orange (High Risk)2x per year
Red (Very High Risk)3x to 4x per year

Clinical Actions

01
Treat to target BP < 130/80 mmHg (Class I recommendation).
02
Initiate SGLT2 inhibitors for GFR ≥ 20 and ACR ≥ 200 (or ACR 30-200 in certain cases) to slow progression.
03
Initiate ACEi or ARB for patients with ACR ≥ 300 (or ACR 30-299 in diabetics).
04
Refer to Nephrology if: GFR < 30 (G4), ACR > 300 (A3), or GFR decline > 5 mL/min/year.

Related Calculators

CKD-EPI Equation (2021)
Creatinine Clearance (Cockcroft-Gault)
Kidney Failure Risk Equation (KFRE)

The Evidence

Primary Guideline

KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.

Kidney Disease: Improving Global Outcomes (KDIGO) • Kidney Int Suppl.. 2013;3(1):1-150. Established the heatmap risk categories based on GFR and Albuminuria.

Race-Independent Updates

New Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race.

Inker LA et al. • NEJM. 2021;385:1737-1749. Landmark study replacing the older CKD-EPI 2009 equation to promote equity in nephrology.

Origins & History

KDIGO Initiative

KDIGO is an independent non-profit organization that develops and implements evidence-based clinical practice guidelines in kidney disease. Before the 2012 update, CKD was staged primarily by GFR alone (KDOQI 2002); the addition of Albuminuria was a pivotal change reflecting modern evidence on mortality risk.

Last Comprehensive Review: 2026-07-17

In Recent Clinical News

Scanning Medical Journals

No new significant updates or guidelines matching this topic were found today. We will check again soon.