Albumin, 24-Hour Urine without Creatinine
The 24-hour urine albumin test quantifies total albumin excretion over a diurnal cycle, the reference method for assessing glomerular permeability. Values ≥30 mg/24 h define albuminuria (KDIGO A2/A3), predict CKD progression and cardiovascular risk, guide renoprotective therapy, and are used to diagnose diabetic nephropathy and monitor treatment response.
1
Biomarkers
Urine (24-hour)
Sample
2–3 business days
Turnaround
No
Fasting
What is the 24-Hour Urine Albumin test?
The 24-Hour Urine Albumin Test quantifies total albumin excretion over a complete diurnal cycle, providing a time-integrated measure of glomerular permeability that is less subject to the concentration variability inherent in random spot samples. It is the reference method for albuminuria assessment when precision is critical or when spot albumin-to-creatinine ratios yield borderline or discordant results. Practitioners order this test to diagnose and stage chronic kidney disease, to detect the onset of diabetic or hypertensive nephropathy before glomerular filtration rate declines, and to monitor the efficacy of renoprotective interventions. Unlike spot samples, the 24-hour collection captures diurnal variation and is unaffected by differences in urine concentration, making it particularly useful for longitudinal tracking and for patients in whom creatinine excretion may be atypical — children, individuals with extremes of muscle mass, or those with fluctuating hydration.
What does the 24-Hour Urine Albumin test measure?
Albumin is a 66-kilodalton plasma protein synthesised by the liver and normally retained in the circulation by the glomerular filtration barrier. The healthy glomerulus restricts passage of negatively charged, intermediate-sized proteins; only trace amounts of albumin — typically under 30 mg per day — appear in the final urine. When podocyte integrity or glomerular basement-membrane charge selectivity is compromised, albumin filtration increases, and its excretion rises in proportion to the severity of glomerular injury. Because tubular reabsorption of filtered albumin is limited, increased glomerular permeability is reflected directly in urine albumin concentration.
Urine albumin excretion is the most sensitive early marker of glomerular injury and the cornerstone of chronic kidney disease staging. Persistent albuminuria defines CKD categories A2 (30–300 mg/d, moderately increased) and A3 (>300 mg/d, severely increased), both of which independently predict progression to end-stage kidney disease and cardiovascular events. Albuminuria is also the earliest detectable sign of diabetic nephropathy and a target for renoprotective therapy with renin-angiotensin-aldosterone system inhibitors and sodium-glucose cotransporter-2 inhibitors. Serial measurements guide treatment titration and monitor response.
Why is the 24-Hour Urine Albumin test ordered?
- Baseline and annual screening of patients with type 1 or type 2 diabetes mellitus for diabetic nephropathy, as recommended by international diabetes and nephrology guidelines
- Evaluation and staging of chronic kidney disease in patients with hypertension, autoimmune disease, or a family history of renal disease
- Confirmation of persistent albuminuria when a spot albumin-to-creatinine ratio is borderline (20–40 mg/g) or discordant with clinical findings
- Monitoring response to renin-angiotensin-aldosterone system blockade, SGLT2 inhibitors, or other renoprotective therapy, with repeat collection every three to six months
- Pre-eclampsia assessment in pregnancy when protein quantification is required and spot protein-to-creatinine ratio is unavailable or inconclusive
- Evaluation of glomerulonephritis, nephrotic syndrome, or other primary renal disorders where precise, time-integrated albumin excretion informs diagnosis and prognosis
- Paediatric or geriatric patients and individuals with unusual muscle mass or creatinine excretion, in whom spot ratios may be less reliable
- Cardiovascular risk stratification in patients with established atherosclerotic disease, since albuminuria independently predicts adverse cardiovascular outcomes
Sample collection and turnaround
Sample type
Urine (24-hour)
Fasting required
No
Collection method
At-home collection kit
Turnaround
2–3 business days
Collection notes
The patient receives a collection container and written instructions. Begin the collection by discarding the first morning void, then collect all subsequent urine over the next 24 hours, including the first void the following morning at the same time. Record the exact start and end times on the container label. Keep the container refrigerated or on ice throughout the collection period. Avoid vigorous exercise, defer if febrile or menstruating, and maintain usual diet and hydration. Because creatinine is not measured in this assay, completeness relies entirely on patient adherence — provide clear verbal and written guidance.
Specimen requirements
Entire 24-hour urine volume in the supplied container. Refrigerate throughout collection. Record total volume and collection interval. Ship refrigerated or with cold packs to the laboratory within 24 hours of completion.
What can affect 24-Hour Urine Albumin results?
The accuracy of 24-hour urine tests depends entirely on complete collection; missed voids or incorrect timing underestimate or overestimate excretion. Creatinine excretion can verify completeness, but this test does not include it, so patient education and adherence are critical.
Strenuous physical activity transiently increases glomerular permeability and albumin excretion; patients should maintain usual activity and avoid intense exercise during the 24 hours.
Fever, infection, and haematuria can all spuriously raise urine albumin; defer collection until the patient is afebrile, asymptomatic, and menstruation has ceased.
Some individuals, particularly adolescents, excrete more albumin when upright; a timed overnight (recumbent) collection can help distinguish orthostatic from pathological proteinuria when clinical suspicion arises.
Acute high-protein meals can transiently increase glomerular filtration and albumin excretion; instruct patients to maintain their usual diet rather than making abrupt changes during the collection.
Severe dehydration can reduce glomerular filtration and concentrate urine, potentially affecting excretion; normal hydration should be maintained throughout the 24 hours.
What do 24-Hour Urine Albumin results mean?
Elevated
Albuminuria ≥30 mg/24 h indicates glomerular injury. Values of 30–300 mg/24 h (moderately increased albuminuria, KDIGO A2) are typical of early diabetic or hypertensive nephropathy and warrant initiation or intensification of renoprotective therapy. Excretion >300 mg/24 h (severely increased albuminuria, KDIGO A3) reflects more advanced glomerular injury, seen in overt diabetic nephropathy, glomerulonephritis, and nephrotic-range proteinuria; these patients require subspecialty nephrology input. Transient elevations occur with fever, vigorous exercise, and urinary-tract infection and should be confirmed with a repeat collection once the acute process has resolved.
Normal
A result <30 mg/24 h does not exclude all renal disease — tubular disorders, some acute kidney injury, and early obstruction may present with minimal albumin excretion. Interpret alongside serum creatinine, estimated GFR, urinalysis, and clinical context.
Reduced
Albumin excretion below 30 mg/24 h is normal and indicates intact glomerular permeability. In patients previously albuminuric, a reduction to this range after therapy represents successful renoprotection and improved prognosis.
Note: Because this test does not include creatinine, collection completeness cannot be biochemically verified; emphasise patient education and written instructions. A single elevated result should be confirmed with a second collection within three months before diagnosing persistent albuminuria. Serial results are most informative when collection technique is standardised and the same laboratory performs the assay.
Frequently asked questions
The 24-hour collection is the reference method and captures diurnal variation without relying on creatinine correction, making it more accurate when spot ratios are borderline, when creatinine excretion is atypical, or when precise longitudinal monitoring is required.
How to access the 24-Hour Urine Albumin test
The 24-Hour Urine Albumin reference page is free and open to all practitioners. Create a free practitioner account to see pricing, save tests to your list, and generate requisition forms. Verification takes 1–2 business days.
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Published: October 7, 2026
Last reviewed: October 7, 2026
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. (2024)
- American Diabetes Association. Standards of care in diabetes — microvascular complications and foot care. Diabetes Care. (2025)
- National Kidney Foundation. KDOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. (2002)
- Lambers Heerspink HJ, et al. Albuminuria assessed from first-morning-void urine samples versus 24-hour urine collections as a predictor of cardiovascular morbidity and mortality. Am J Epidemiol. (2008)
This content is for licensed healthcare practitioners only and does not constitute medical advice. Clinical decisions should be based on the full clinical picture and not on any single test result.
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