The urine albumin-to-creatinine ratio (uACR) is a quantitative measure of albumin excretion in a spot urine sample, normalized to creatinine concentration to correct for urine dilution. It serves as a reliable surrogate for 24-hour urine albumin excretion and is the preferred method for detecting and monitoring albuminuria in clinical practice. Values are typically reported in mg/g or mg/mmol and are used to stage chronic kidney disease (CKD) and assess cardiovascular risk. Under normal physiologic conditions, the glomerular filtration barrier restricts passage of albumin (a large, negatively charged protein) into the filtrate, and any small amount that does cross is largely reabsorbed by proximal tubular cells, resulting in minimal urinary albumin excretion (less than 30 mg/g creatinine). Glomerular injury, increased intraglomerular pressure, endothelial dysfunction, or tubular reabsorptive defects disrupt this balance, leading to elevated albumin in the urine. Creatinine is used as the denominator because its urinary excretion is relatively constant per unit of muscle mass, allowing a single random specimen to approximate a timed collection.
This test measures how much of a protein called albumin is leaking into your urine compared to a waste product called creatinine. Healthy kidneys keep most albumin in the blood, so finding too much in the urine can be an early sign that the kidneys are under stress. A single elevated result does not necessarily mean kidney disease, as temporary factors like exercise or infection can raise the level, which is why doctors often repeat the test. If the level stays high over time, it may indicate a need for closer monitoring or further evaluation of kidney and heart health. Keeping blood pressure and blood sugar well controlled are among the most important ways to protect the kidneys.
When elevated: Elevated uACR indicates increased glomerular permeability or impaired tubular reabsorption of albumin, signaling potential kidney injury or dysfunction. Persistently elevated values are associated with accelerated CKD progression, increased risk of cardiovascular events, and higher all-cause mortality. Moderate to severe albuminuria warrants further evaluation for underlying causes such as diabetic nephropathy, hypertensive nephrosclerosis, or primary glomerular disease. When low: A low or normal uACR (less than 30 mg/g) is generally reassuring and suggests intact glomerular filtration barrier function and adequate tubular reabsorption. Very low values have no established adverse clinical significance. Normal results in high-risk individuals (e.g., those with diabetes or hypertension) support continued surveillance rather than complacency, as albuminuria can develop over time.
Albumin/creatinine ratio is not directly a performance marker, but elevated levels may signal overtraining-induced kidney stress, dehydration, or underlying metabolic dysfunction that can impair recovery and long-term health. It's most relevant for endurance athletes or those with intense training volumes, as it helps detect early kidney injury before symptoms develop, supporting sustainable training and longevity.
Turnaround Time
4 days (up to 14 days)
Fasting Required
No
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$13.86$40
2.9× less than retail
Versus the typical direct-to-consumer retail price for this test (illustrative — consumer prices vary by provider and region).
$13.86
$17.00
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