Synopsis
Confirm chronic kidney disease correctly, stage both filtration and albuminuria, identify its cause, and recognise patients needing urgent or specialist assessment.
- CKD requires a kidney structural or functional abnormality present for more than 3 months; one low eGFR during acute illness is acute kidney injury until chronicity is demonstrated.
- Classify eGFR as G1 at least 90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29 and G5 below 15 mL/min/1.73 m², but G1 or G2 alone is not CKD without another marker of damage.
- Pair the G category with urine albumin:creatinine ratio: A1 below 3, A2 3–30 and A3 above 30 mg/mmol; the combination predicts renal and cardiovascular risk better than either value alone.
Key red flags
Pulmonary oedema, dangerous hyperkalaemia, severe metabolic acidosis, uraemic encephalopathy or pericarditis requires immediate hospital and renal assessment, not outpatient confirmation of chronicity.
Investigation priorities
Confirm chronicity, establish the G category and detect acute or sustained progression.
Management branches
An adult has a first creatinine-based eGFR below 60 mL/min/1.73 m².
- Check prior results, current illness, hydration, urine output, medicines and obstruction symptoms, and assess immediately for AKI or a renal emergency.
- Repeat renal function within the NICE-recommended acute exclusion interval when deterioration is new, adjusting urgency to the clinical picture.
Risk, progression, albuminuria, haematuria, hypertension or suspected cause exceeds routine primary-care management.