CKD is a sustained (more than 3 months) decline in kidney function or the presence of kidney damage. The kidneys filter the blood less well, and over time this affects the whole body.
The insidious thing about CKD is that it runs without symptoms for a long time — a person feels fine until a large part of function is lost. That is why it is found through tests: eGFR and urine albumin.
Reference ranges
CKD stages by eGFR (mL/min/1.73 m²):
| G1–G2 | ≥ 60 — normal or mild decrease* |
| G3a–G3b | 30 – 59 — moderate decrease |
| G4 | 15 – 29 — severe decrease |
| G5 | < 15 — kidney failure |
What an elevated level means
A decline in kidney function is indicated by a sustained eGFR below 60 and/or albumin in the urine.
The main causes of CKD: diabetes and high blood pressure account for the majority of cases. Also — glomerulonephritis, polycystic kidney disease, long-term use of some painkillers.
What to do: control blood pressure and glucose, discuss medications with your doctor (some drugs protect the kidneys), avoid nephrotoxic agents, and be followed by a nephrologist.
What a low level means
In the context of CKD there are no "low" values — it is always about a decline in function. A high eGFR (above normal) is usually a good sign, though a very high one can occur with hyperfiltration in early-stage diabetes.
How the test is done
CKD is detected by two measures: eGFR (calculated from creatinine or cystatin C) and urine albumin (the albumin-to-creatinine ratio).
Persistence of the changes matters — they are confirmed on a repeat test after 3 months. A single "bad" result is not yet a diagnosis.
What affects the value
- Diabetes — the number-one cause of CKD worldwide.
- High blood pressure — the second main cause and, at the same time, a consequence.
- Age — filtration naturally declines over the years.
- Painkillers (NSAIDs) — long-term use harms the kidneys.
- Dehydration and nephrotoxic medications — accelerate the damage.
Calculate using this marker
Calculators where CKD is used directly:
Frequently asked questions
How do I know if I have CKD?
From tests: a persistently reduced eGFR (below 60 for more than 3 months) and/or albumin in the urine. There are usually no symptoms in the early stages, so CKD is found in the lab. You can calculate eGFR in our calculator.
Can CKD be cured?
Advanced stages cannot be fully reversed, but the decline in function can be slowed substantially: control blood pressure and glucose, use the right medications (some protect the kidneys), and avoid nephrotoxic agents. The earlier it is found, the better the outlook.
What does stage G3 mean?
It is a moderate reduction in filtration (eGFR 30–59). It does not yet require dialysis, but it is an important signal to bring blood pressure, glucose and medications under control and to be monitored regularly by a doctor to prevent progression.