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Chronic kidney disease (CKD)
CKD is kidney damage lasting more than 3 months, classified by eGFR and albuminuria, and slowed mainly with an ACEi or ARB, an SGLT2 inhibitor and blood-pressure control — while its complications are treated: anaemia, bone-mineral disease, acidosis and hyperkalaemia.
Why it matters in the exam
CKD questions first test classification: G stages by eGFR (G3a 45–59, G3b 30–44, G4 15–29, G5 below 15) and A stages by albuminuria (A2 30–300 mg/g, A3 above 300). Then come the drugs that slow progression: an ACEi or ARB in every patient with albuminuria, an SGLT2 inhibitor from an eGFR of 20 and above (also without diabetes), and finerenone in type 2 diabetes with albuminuria despite an ACEi. A standard distractor is combining an ACEi with an ARB — not allowed, since it increases hyperkalaemia and AKI without benefit.
Complications are the second part. In bone-mineral disease (CKD-MBD) phosphate is high, calcium low, PTH high and active vitamin D (calcitriol) deficient, so phosphate is lowered with diet and binders. In anaemia iron is replaced first, and only then is an ESA considered, without aiming for a haemoglobin above 11.5 g/dL because that raises the risk of stroke. Drug adjustments must also be remembered: metformin — reduce the dose at eGFR 30–44 and stop below 30; avoid NSAIDs. The decision to start dialysis rests on symptoms and complications, not on an eGFR number alone, and referral to a nephrologist comes earlier, usually at an eGFR below 30.
Key points
- CKD: eGFR below 60 or albuminuria 30 mg/g or more for more than 3 months.
- Slowing: ACEi or ARB with albuminuria, SGLT2 inhibitor from eGFR 20, finerenone in diabetes with albuminuria.
- CKD-MBD: high phosphate, low calcium, high PTH.
- Anaemia: iron first, ESA when Hb is below 10, not above 11.5 g/dL.
- Metformin: reduce at eGFR 30–44, stop below 30.
Summary table
| Topic | Value / criterion | Treatment | Exam note |
|---|---|---|---|
| Definition | eGFR below 60 or albuminuria 30 mg/g or more, for over 3 months | Find the cause (diabetes, hypertension, glomerular) | Stages G1–G5 and A1–A3 |
| Slowing progression | Albuminuria A2–A3 | ACEi or ARB at the maximum tolerated dose | Do not combine an ACEi with an ARB |
| SGLT2 inhibitor | eGFR 20 or more | Dapagliflozin or empagliflozin | Protects the kidney even without diabetes |
| Blood pressure | Systolic below 120 if tolerated (KDIGO) | ACEi/ARB, diuretic, calcium-channel blocker | A small rise in creatinine when starting an ACEi is expected |
| CKD-MBD | High phosphate, low calcium, high PTH | Phosphate restriction, phosphate binders, vitamin D | Secondary hyperparathyroidism |
| Anaemia | Low Hb, usually normocytic | Iron first; ESA when Hb is below 10 | Do not aim for Hb above 11.5 g/dL |
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Sources
- KDIGO Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease, 2024 — Definition, GFR and albuminuria categories, slowing progression and complications
- KDIGO Clinical Practice Guideline for Diabetes Management in CKD, 2022 — SGLT2 inhibitors, finerenone and metformin dosing
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Chronic Kidney Disease
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.