Urine Albumin-to-Creatinine Ratio (ACR)

Why This Test Matters

Kidneys normally filter waste and extra fluid from your blood. If they’re damaged, they may allow small amounts of protein (like albumin) to appear in urine. This test helps identify early signs of kidney issues, such as diabetic nephropathy or glomerulonephritis, before symptoms become severe.

How the Test Works

A small urine sample is collected (often during a 24-hour period or a single random sample). The lab measures albumin and creatinine levels separately and calculates their ratio. Higher ratios may signal kidney problems, while normal ratios suggest healthy kidney function.

What to Expect Before the Test

No special preparation is needed unless instructed by your doctor. You may be asked to collect urine over 24 hours (morning to morning) or provide a single random sample. Avoid certain medications or foods that could affect results (e.g., high-protein diets or certain supplements).

Possible Results and Next Steps

Results are typically reported as a ratio (e.g., mg/mmol). A high ratio may prompt further kidney tests, like blood tests or imaging. A normal ratio doesn’t guarantee kidney health, so follow-up may still be needed if you have risk factors (e.g., diabetes, high blood pressure).