About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- CKD: eGFR <60 mL/min/1.73m² for ≥3 months (or structural/functional abnormality). Staged G1–G5 by eGFR + A1–A3 by ACR
- Commonest causes: diabetic nephropathy (~40%), hypertension (~25%), glomerulonephritis, polycystic kidney disease
- ACEi/ARB: first-line for proteinuria (ACR >30) — slow progression. Monitor K⁺ and creatinine (accept up to 25% rise)
- SGLT2 inhibitors (dapagliflozin): proven to slow CKD progression regardless of diabetes status (DAPA-CKD trial)
- BP target: <140/90 (or <130/80 if ACR ≥70). Statin for CVD risk reduction
- Refer to nephrology: eGFR <30, ACR ≥70, progressive decline (>5 mL/min/year), or suspected renal artery stenosis
Overview
Chronic kidney disease is defined as abnormalities of kidney structure or function present for >3 months with implications for health. It is staged by eGFR (G1–G5) and albuminuria category (A1–A3). CKD is often asymptomatic until advanced stages (G4–G5) and is a major risk factor for cardiovascular disease — most CKD patients will die from CVD before reaching end-stage renal disease (ESRD). Management focuses on slowing progression, managing complications, and cardiovascular risk reduction.
Epidemiology
CKD affects approximately 7% of the UK adult population — around 3 million people. The majority have early-stage disease (G3). Prevalence increases with age (>30% of those >75 years have eGFR <60). Approximately 65,000 people in the UK are on renal replacement therapy (dialysis or transplant). Diabetes is the single largest cause (~40%), followed by hypertension, glomerulonephritis, and adult polycystic kidney disease. CKD disproportionately affects South Asian and Black populations.
Clinical Features
Symptoms
Often asymptomatic in early stages (G1–G3) — detected on screening bloods
Fatigue and lethargy
Nocturia and polyuria (loss of concentrating ability)
Peripheral oedema
Pruritus (uraemic itch — advanced CKD)
Nausea, anorexia, weight loss (advanced)
Restless legs
Bone pain (renal osteodystrophy)
Signs
Hypertension
Pallor (renal anaemia)
Peripheral oedema
Excoriation marks (pruritus)
Arteriovenous fistula or peritoneal dialysis catheter (established renal failure)
Uraemic fetor, pericardial rub, encephalopathy (end-stage — rare if monitored)
Investigations
First-line
eGFR (from serum creatinine)Stage: G1 ≥90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29, G5 <15 mL/min. Confirm with repeat at ≥3 months
Urine ACRA1 <3 (normal), A2 3–30 (microalbuminuria), A3 >30 (macroalbuminuria). First morning void. Quantifies proteinuria and guides ACEi/ARB use
UrinalysisHaematuria + proteinuria suggests glomerular disease — refer to nephrology
Second-line
BloodsFBC (anaemia), calcium, phosphate, PTH (secondary hyperparathyroidism), vitamin D, bicarbonate (acidosis), lipid profile
Renal USSAssess kidney size (small = chronic), exclude obstruction, polycystic kidneys. Asymmetric kidneys suggest renal artery stenosis
HbA1c + glucoseIf diabetic nephropathy suspected
Specialist
Immunology screenANA, ANCA, complement, immunoglobulins, serum electrophoresis — if glomerulonephritis suspected
Renal biopsyIf cause unclear, rapidly progressive GN, or nephrotic-range proteinuria
Renal artery Doppler / MRAIf renovascular disease suspected (asymmetric kidneys, flash pulmonary oedema, resistant HTN)
1
Slow progression
- ACEi or ARB if ACR ≥30 mg/mmol (or ≥3 in diabetes) — titrate to maximum tolerated dose
- Accept up to 25% rise in creatinine and K⁺ up to 6.0 after starting ACEi — beyond this, investigate
- SGLT2 inhibitor (dapagliflozin 10 mg): add if ACR ≥22.6 and eGFR ≥20 — proven renoprotective (NICE TA775)
- BP target: <140/90 (or <130/80 if ACR ≥70)
- Optimise glycaemic control in diabetes (HbA1c targets per NICE NG28)
2
Cardiovascular risk management
- Atorvastatin 20 mg for primary prevention (CKD is a CVD risk equivalent)
- Smoking cessation
- Lifestyle: exercise, weight management, low-salt diet (<6 g/day)
- Antiplatelet therapy only for secondary prevention (not primary)
3
Manage complications
- Anaemia: check ferritin and TSAT; IV iron if deficient; erythropoietin-stimulating agents (ESA) if Hb <100 and iron replete
- CKD-mineral bone disease: phosphate binders (calcium acetate, sevelamer), active vitamin D (alfacalcidol) if PTH rising, dietary phosphate restriction
- Acidosis: sodium bicarbonate if bicarb <20 mmol/L
- Fluid overload: loop diuretics (furosemide — higher doses needed as eGFR falls)
4
Renal replacement therapy (G5 or symptomatic G4)
- Prepare from eGFR <20: dialysis access planning (AV fistula creation ≥6 months before anticipated need), transplant workup
- Haemodialysis (3×/week in-centre or home), peritoneal dialysis (daily at home)
- Renal transplant: gold standard if suitable — living donor preferred (better outcomes)
- Conservative management: appropriate for some frail/elderly patients — focus on symptom control and quality of life
Complications
- Cardiovascular disease: Leading cause of death in CKD — risk increases 2–3× from G3 onwards
- Renal anaemia: Reduced erythropoietin production → normocytic normochromic anaemia
- CKD-mineral bone disease: Hyperphosphataemia, hypocalcaemia, secondary hyperparathyroidism → renal osteodystrophy
- Hyperkalaemia: Impaired potassium excretion — exacerbated by ACEi/ARB and potassium-sparing diuretics
- Metabolic acidosis: Impaired acid excretion
- Fluid overload: Sodium and water retention
UKMLA Exam Tips
- 1CKD staging: know G1–G5 eGFR thresholds and A1–A3 ACR thresholds — exam staple
- 2ACEi/ARB: start if ACR ≥30 (or ≥3 in diabetes). Accept up to 25% creatinine rise — beyond this, investigate (renal artery stenosis?)
- 3SGLT2 inhibitors are now recommended for CKD with proteinuria regardless of diabetes — this is relatively new and high-yield
- 4Most CKD patients die from CVD, not ESRD — cardiovascular risk management is as important as renoprotection
- 5Renal anaemia is normocytic. Treat with IV iron first, then ESA if iron replete and Hb still <100
- 6Secondary hyperparathyroidism: high PTH, high phosphate, low calcium, low vitamin D — treat phosphate first
- 7Nephrology referral criteria: eGFR <30, ACR ≥70, eGFR declining >5/year, haematuria+proteinuria, refractory HTN, suspected renal artery stenosis
practicetest your knowledge on ckdApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — renal and beyond.
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