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.
- Repeat a newly reduced eGFR promptly to exclude acute deterioration, then use results separated by at least 90 days to establish stable CKD; inspect prior blood tests and clinical context.
- Measure urine ACR rather than total protein for initial proteinuria detection, preferably on an early-morning specimen when confirmation is required, and interpret infection, menstruation, exercise and diabetes context.
- Do not apply creatinine-based eGFR uncritically at extremes of muscle mass, amputation, malnutrition, oedema or rapidly changing renal function; discuss measured GFR when accuracy would change a major decision.
- Aetiology matters: diabetes, hypertension, glomerular disease, obstruction, medicines, inherited disease and systemic inflammation need different investigations and disease-specific treatment.
- Refer an adult for specialist CKD assessment, considering wishes and comorbidity, if 5-year KFRE risk is above 5%; ACR is at least 70 mg/mmol unless diabetes is the known cause and is already appropriately treated; ACR is above 30 mg/mmol with haematuria; eGFR falls by at least 25% with a category change within 12 months or by at least 15 mL/min/1.73 m² per year; blood pressure remains above the individual target despite at least 4 antihypertensives at therapeutic doses; or rare/genetic CKD or renal-artery stenosis is known or suspected.
- Hyperkalaemia, pulmonary oedema, severe acidosis, uraemic complications or a rapidly rising creatinine are emergencies and should not wait for routine CKD staging.
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.
A rapid creatinine rise or oliguria indicates possible acute kidney injury superimposed on CKD and needs same-day evaluation of volume, obstruction, sepsis and nephrotoxins.
Visible haematuria, persistent non-visible haematuria with substantial albuminuria, or rapidly progressive renal impairment may signal glomerulonephritis or urological malignancy and requires the appropriate urgent pathway.
New bilateral hydronephrosis, an obstructed solitary kidney or infected obstruction is a time-critical urological problem; seek drainage advice while treating sepsis and electrolyte disturbance.
Severe hypertension with retinal, neurological, cardiac or renal target-organ injury is a hypertensive emergency and should not be managed as routine CKD blood-pressure review.
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.
- If stable, document at least two results separated by 90 days or another unequivocal chronic marker before labelling CKD.
- Stage with both eGFR and ACR, determine likely cause, review cardiovascular risk and agree a stage- and trajectory-based monitoring plan.
Risk, progression, albuminuria, haematuria, hypertension or suspected cause exceeds routine primary-care management.
- Calculate kidney-failure risk where valid and document the sustained eGFR and ACR trajectory rather than sending one isolated result.
- Apply NICE NG203 exactly: 5-year KFRE risk above 5%; ACR at least 70 mg/mmol unless due to diabetes and already appropriately treated; ACR above 30 mg/mmol with haematuria; sustained eGFR fall at least 25% with category change within 12 months or at least 15 mL/min/1.73 m² per year; hypertension above target despite at least 4 therapeutic-dose agents; known or suspected rare or genetic CKD; or suspected renal-artery stenosis.