24-Hour Urine Albumin

Function

Albumin is a major protein found in the blood. In healthy kidneys, the filtering units (glomeruli) prevent albumin from passing into the urine. However, when the kidneys are damaged, small amounts of albumin leak through the filters, a condition known as microalbuminuria. The 24-Hour Urine Albumin test is the gold standard for quantifying this leakage over a full day, providing a more stable and accurate assessment than a random spot check. It serves as an early 'canary in the coal mine' for kidney disease, often detecting damage years before standard creatinine tests show an abnormality.

Why it is Ordered

This test is essential for screening and monitoring patients with chronic conditions that risk kidney damage, most notably Diabetes Mellitus (Type 1 and 2) and Hypertension (High Blood Pressure). The American Diabetes Association recommends annual screening to detect early-stage Diabetic Nephropathy. Identifying albuminuria early allows for aggressive intervention with ACE inhibitors or ARBs, which can slow or even reverse the progression of kidney disease. It is also used to evaluate systemic vascular health, as albuminuria is a known marker for increased cardiovascular risk.

Associated Conditions

• Diabetic Nephropathy: Kidney damage specifically caused by long-term high blood sugar.
• Hypertensive Nephrosclerosis: Damage to the kidney's small blood vessels due to high blood pressure.
• Glomerulonephritis: Inflammation of the kidney's filtering units.
• Preeclampsia: A pregnancy complication characterized by high blood pressure and protein in the urine.
• Systemic Lupus Erythematosus (SLE): An autoimmune disease that can cause lupus nephritis.