Chronic kidney disease in adults: detection, staging, progression and referral

Clinical scope and defining chronic kidney disease

Chronic kidney disease is defined by persistent abnormalities of kidney structure or function with implications for health. In routine adult practice, this commonly means a sustained reduction in estimated glomerular filtration rate, persistent albuminuria or another marker of kidney damage. A single abnormal creatinine does not establish chronicity and may represent acute kidney injury, dehydration, medication effect or laboratory variation. The first task is therefore to distinguish an acute change from a persistent condition.

CKD is clinically important not only because of possible progression to kidney failure but because it is strongly associated with cardiovascular disease, acute kidney injury and medication-related harm. Many people have stable early-stage disease for years. Communicating risk accurately helps avoid both complacency and unnecessary alarm. Assessment should combine GFR category with albuminuria category because these together provide more useful prognostic information than either measure alone.

Testing kidney function and confirming abnormal results

Clinical laboratories report creatinine-based eGFR with serum creatinine, but the estimate has limitations. It may be less reliable in acute kidney injury, pregnancy, major oedema, severe malnutrition, unusual muscle mass, amputation and some other settings. Interpret the result in clinical context rather than treating the reported eGFR as a direct measurement. Changes close to category boundaries should be confirmed before major decisions are based on them.

Albumin-to-creatinine ratio is the preferred test for detecting low-level proteinuria in most adults. An elevated ACR should be confirmed according to the guideline unless the value is sufficiently high that repeat confirmation is unnecessary. In a newly discovered reduced GFR, repeat testing promptly when acute deterioration is possible, and establish chronicity with previous results or subsequent measurements over time. Urinalysis for haematuria and review of older laboratory data can provide important clues to cause and duration.

Staging, cause and risk of progression

CKD classification combines GFR categories G1 to G5 with albuminuria categories A1 to A3. The combination matters because a person with preserved eGFR but marked albuminuria may have substantial renal and cardiovascular risk, while an older adult with a mildly reduced stable eGFR and little albuminuria may have a different prognosis. Explain the category in terms of likely risk and monitoring rather than using the stage label in isolation.

Look for a plausible cause. Diabetes, hypertension and vascular disease are common, but obstruction, glomerular disease, hereditary kidney disease and medicine-related injury should not be missed. NICE recommends renal ultrasound for selected adults, including those with accelerated progression, haematuria, obstructive symptoms, relevant family history or advanced reduction in GFR. A treatable cause should be pursued because management may differ substantially from generic CKD risk reduction.

Monitoring and identifying progression

Monitoring frequency depends on GFR, ACR, cause, previous rate of decline, comorbidity, intercurrent illness and treatment changes. Stable low-risk disease may need relatively infrequent testing, while advanced CKD, heavy albuminuria or active decline requires closer review. Albuminuria monitoring should be performed when a change is likely to influence management. Patients taking renin-angiotensin system blockers, diuretics or other medicines affecting kidney function need appropriate biochemical monitoring after initiation or dose changes.

NICE defines accelerated progression using sustained change rather than one result. A substantial percentage fall in GFR with movement to a worse category within a year, or a sustained annual fall of about 15 ml/min/1.73 m², is a red flag. To estimate the rate of decline, use several measurements over at least 90 days where the clinical situation permits. An abrupt reduction should first prompt assessment for acute kidney injury, obstruction, volume depletion or a medication-related cause.

Reducing cardiovascular and renal risk

Cardiovascular risk reduction is integral to CKD care. Blood-pressure management, lipid treatment, diabetes care, smoking cessation and physical activity should be addressed through the relevant guidelines. Renin-angiotensin system blockade has a particular role in people with significant albuminuria and in selected comorbid conditions, with potassium and kidney function monitored after treatment changes. Current diabetes and CKD guidance should be consulted for use of SGLT2 inhibitors and other disease-modifying therapies because indications have evolved beyond glucose lowering alone.

Medicines should be reviewed for kidney-dependent dosing, nephrotoxicity and interactions. NSAID exposure is a common avoidable contributor to acute deterioration, especially during intercurrent illness or alongside diuretics and renin-angiotensin system blockers. Patients benefit from clear advice about over-the-counter medicines and what to do when acutely unwell. Avoid broad medication discontinuation rules without clinical context; the aim is to reduce preventable harm while preserving therapies with proven cardiovascular or renal benefit.

Referral and kidney failure risk

Specialist referral is appropriate when findings suggest a diagnosis needing nephrology expertise, when progression is concerning, when albuminuria is severe in relevant contexts, when hypertension remains resistant, when hereditary disease is suspected, or when advanced CKD requires planning. NICE also incorporates kidney failure risk estimation for selected adults because predicted risk can identify people who benefit from specialist assessment even when eGFR alone seems less alarming.

Referral should include the longitudinal eGFR pattern, ACR, blood pressure, urine findings, relevant imaging, medication list and suspected cause. Urgent discussion is appropriate when there is rapid deterioration, severe electrolyte disturbance, suspected glomerulonephritis or another time-sensitive renal presentation. For advanced disease, shared planning may include renal replacement therapy options, conservative kidney management and anticipatory care according to the person’s health status and preferences.

Practice points and limitations

Common errors include labelling CKD from a single abnormal creatinine, ignoring albuminuria when eGFR is preserved, failing to distinguish acute kidney injury from chronic decline, overlooking nephrotoxic or dose-sensitive medicines, and delaying referral when the trajectory is clearly worsening. A useful CKD review records eGFR category, ACR category, likely cause, trend, blood pressure, medication safety and the planned interval for monitoring.

This resource summarises the adult assessment and management principles in NICE NG203. It does not reproduce all category-specific monitoring intervals, referral criteria or medicine indications. The full guideline, current diabetes and hypertension guidance, local renal pathways and current product information should be used for individual treatment decisions.

Communication, medication safety and intercurrent illness

CKD is often discovered incidentally, and the way it is explained influences future engagement. Avoid presenting a mildly reduced eGFR as imminent kidney failure. Explain the GFR and albuminuria categories, the observed trend and the factors that make progression more or less likely. Patients benefit from knowing which results are being monitored and why. Where kidney failure risk estimation is used, place the percentage in context and explain how it influences referral or planning.

Medication safety requires an accurate, current list. Review prescribed medicines, over-the-counter NSAIDs, supplements and drugs that require renal dose adjustment. A reduction in eGFR can alter the safe use of antimicrobials, anticoagulants, diabetes treatments and analgesics. When a medicine with renal or electrolyte effects is started or increased, record the intended laboratory monitoring interval. If a drug is temporarily interrupted during acute illness, the plan should include when and by whom it will be restarted or reviewed.

Intercurrent illness is a common point at which stable CKD becomes acute kidney injury. Vomiting, diarrhoea, sepsis, poor intake, urinary obstruction and newly introduced medicines should prompt timely reassessment. Compare creatinine with the person’s baseline rather than relying on the current eGFR category alone. After an acute deterioration, confirm recovery or establish a new baseline and reconsider the monitoring schedule. Persistent change after an acute episode may represent progression or previously unrecognised structural disease and should not be dismissed once the immediate illness has resolved.

Blood and urine results should be interpreted alongside the patient’s broader health trajectory. Declining muscle mass can lower serum creatinine and make creatinine-based eGFR appear more reassuring, while substantial muscularity can have the opposite effect. Where the estimate seems inconsistent with the clinical picture and the result would change management, seek an alternative assessment strategy or specialist advice. The principle is to use eGFR as a useful estimate with known limitations, not as an infallible measurement of kidney function.