Urine Microalbumin / ACR
The albumin-to-creatinine ratio (ACR) is a spot urine test that detects small amounts of albumin leaking through the kidney filter — the earliest sign of diabetic nephropathy, hypertensive kidney disease, and glomerular disease. ACR is far more convenient than a 24-hour urine collection and gives equivalent information. It is recommended annually for anyone with diabetes or chronic hypertension.
Reference Ranges
Male
0 – 30
mg/g
Female
0 – 30
mg/g
Child
0 – 30
mg/g
Reference ranges may vary by laboratory. Always compare with the range printed on your lab report.
What Low Levels Mean
ACR below 30 mg/g is normoalbuminuria — no significant albumin in the urine. This is the desirable result. In someone with diabetes or hypertension it means the kidney filter is intact; continue routine annual screening.
What High Levels Mean
ACR 30–300 mg/g is moderately increased albuminuria (previously called microalbuminuria) and is the earliest detectable sign of diabetic kidney disease. Above 300 mg/g is severely increased albuminuria (previously called macroalbuminuria). Confirmed elevation on two of three samples over 3–6 months warrants ACE inhibitor or ARB therapy and tighter glucose and blood pressure control.
Frequently Asked Questions
How is the urine sample collected?
A random spot urine sample is sufficient — early morning is preferred to minimize variability. Both albumin and creatinine are measured and the ratio is reported. There is no need for a 24-hour urine collection for routine screening.
What can cause a falsely high ACR?
Vigorous exercise in the preceding 24 hours, fever, heart failure, menstruation, urinary tract infection, and very high blood glucose can all transiently raise urine albumin. A positive result is considered real only if confirmed on 2 of 3 samples over 3–6 months, after excluding these transient causes.
Does a high ACR mean I have kidney failure?
No. ACR measures early, reversible kidney damage — long before eGFR drops or creatinine rises. A persistently elevated ACR means you have kidney damage that is at risk of progressing. Starting an ACE inhibitor or ARB, controlling glucose and blood pressure, and addressing other risk factors can slow or halt progression.
This information is for educational purposes only and should not replace professional medical advice. Always consult your doctor for interpretation of your test results.
Read Full Medical Disclaimer →