KDIGO Risk Heat Map
GFR category × albuminuria category = CKD risk.
Medically reviewed by Dr. Rishi Kumar Kafle, MBBS, MD, FASN · Last reviewed June 2026
The KDIGO heat map grades the risk of CKD getting worse by combining two measures: the GFR category (G1–G5) and the albuminuria category (A1–A3). Two people with the same eGFR can sit at very different risk depending on how much albumin is in the urine.
The Two Axes
The heat map has two axes. Going down the rows is the GFR category, from G1 (normal or high filtration) to G5 (kidney failure) — the same CKD stages set by your eGFR. Going across the columns is the albuminuria category, which measures how much protein leaks into the urine.
Albuminuria is measured as a urine albumin-to-creatinine ratio (uACR): A1 is under 30 mg/g (normal to mildly increased), A2 is 30–300 mg/g (moderately increased), and A3 is over 300 mg/g (severely increased). The two axes capture different things — eGFR shows how much the kidneys filter, while albuminuria shows whether the filter is leaking — so reading them together gives a fuller picture than either alone.
| Category | uACR | Meaning |
|---|---|---|
| A1 | < 30 mg/g | Normal to mildly increased |
| A2 | 30–300 mg/g | Moderately increased |
| A3 | > 300 mg/g | Severely increased |
The Risk Grid
| GFR category | A1 (<30 mg/g) | A2 (30–300 mg/g) | A3 (>300 mg/g) |
|---|---|---|---|
| G1 (≥90) | Low | Moderate | High |
| G2 (60–89) | Low | Moderate | High |
| G3a (45–59) | Moderate | High | Very high |
| G3b (30–44) | High | Very high | Very high |
| G4 (15–29) | Very high | Very high | Very high |
| G5 (<15) | Very high | Very high | Very high |
Risk rises as you move down (lower eGFR) and to the right (more albuminuria). A low eGFR with normal albuminuria carries less risk than the same eGFR with heavy albuminuria.
How to Read the Four Risk Levels
The colours in the original KDIGO chart correspond to four bands of risk:
- Low (green) — for example G1 or G2 with A1. Routine monitoring is usually enough.
- Moderate (yellow) — such as G3a with A1, or G1–G2 with A2. Closer follow-up is sensible.
- High (orange) — such as G3b with A1, or G3a with A2. More frequent review is typical.
- Very high (red) — such as G4–G5, or any stage with A3. Specialist care is usually involved.
The bands describe the risk of CKD progressing and of related complications — they are a guide to how closely to watch, not a prediction for any one person. Your clinician sets the actual monitoring plan using these bands alongside your age, blood pressure, and overall health.
Why Two People With the Same eGFR Differ
This is the key insight of the heat map. Imagine two people, both at G3a with an eGFR of 50. One has A1 albuminuria and sits in the moderate band; the other has A3 albuminuria and sits in the very-high band. Their filtration is identical, yet their risk is not, because heavy albuminuria signals active kidney damage. Looking at eGFR alone would miss this difference entirely — which is exactly why staging pairs the GFR category with an albuminuria category rather than relying on the filtration number on its own.
What the Heat Map Does Not Decide
The grid grades risk; it does not, by itself, set treatment or predict outcomes. A “very high” cell does not mean dialysis is imminent — the timing of dialysis depends on symptoms and eGFR, and many people in the higher-risk cells remain stable with good management. The heat map is best understood as a way to focus attention: it tells you and your clinician how closely to monitor and how aggressively to manage the underlying causes.
How Clinicians Use the Heat Map
In practice, the heat map turns two lab results into a shared plan. Once your GFR category and albuminuria category are known, the cell where they meet suggests how often kidney function should be rechecked and whether a referral to a specialist is worth considering. A low-risk green cell usually means routine annual checks; the orange and red cells call for more frequent monitoring and tighter control of blood pressure and any underlying cause such as diabetes. The grid does not replace clinical judgement — it focuses it, giving you and your clinician a common reference point for what to watch and how closely.
Tracking Your Position Over Time
Your place on the heat map can change, and the direction matters. Improving albuminuria — often a sign that treatment of the underlying cause is working — can move you to the left, into a lower-risk column, even if your eGFR is steady. A falling eGFR moves you down into a higher-risk row. Because both axes can shift, the most useful view is your trend across several results rather than a single snapshot. Re-checking both measures periodically is what lets your care team see whether the picture is stable, improving, or in need of a change in management.
Measure Your Albuminuria
Use the albumin/creatinine ratio calculator to find your A category, then read it against your GFR stage. Together they place you on the grid above — and if you do not yet know your filtration, estimate it with the eGFR calculator first.