Urine albumin-creatinine ratio (UACR)
A urine test that measures how much of the blood protein albumin is leaking into the urine, corrected for how dilute the sample is. A raised ratio is one of the earliest signs of kidney damage, especially from diabetes or high blood pressure, so it is a key screening and monitoring test for kidney health.
What it measures
Healthy kidneys keep albumin, the main protein in the blood, out of the urine. When the tiny filters of the kidney (the glomeruli) begin to be damaged, small amounts of albumin start to leak through — and this happens early, often before kidney function measured by creatinine or eGFR has fallen. The urine albumin-creatinine ratio measures the albumin in a single urine sample and divides it by the urine creatinine, which corrects for how concentrated or dilute the sample happens to be. This makes a random ('spot') urine sample almost as reliable as a full 24-hour collection, which is why it is the preferred test. UACR is a cornerstone of kidney-health screening, particularly in people with diabetes or high blood pressure, where it is checked at least yearly to catch damage early. A moderately raised ratio (once called microalbuminuria) is the earliest routine sign that the kidneys are under strain, and it is also an independent warning marker for cardiovascular risk. A very high ratio signals more advanced kidney damage or heavy protein loss. Because it can be transiently raised by fever, infection, exercise or menstrual blood, a raised result is usually confirmed on a repeat sample.
What a high value can mean
- Moderately increased albumin (30–300 mg/g) — the earliest routine sign of kidney damage, often called microalbuminuria; common in diabetes and high blood pressure.
- Severely increased albumin (>300 mg/g) — more advanced kidney damage or heavy protein leak, overlapping with proteinuria.
- Diabetic or hypertensive kidney disease — the classic settings where UACR is monitored.
- Glomerular disease — inflammation or damage of the kidney filters.
- Transient causes — fever, urinary infection, heavy exercise, or menstrual contamination; a reason to repeat before acting.
What a low value can mean
- Normal (<30 mg/g) — the expected, reassuring result; the kidney filters are holding albumin back.
- A falling ratio on treatment — can show that blood-pressure or diabetes control (or medicines that protect the kidney) are working.
When to discuss with a doctor
A raised urine albumin-creatinine ratio is one of the most useful early warnings in medicine, because it can flag kidney damage before symptoms and before eGFR falls, and it also marks higher cardiovascular risk. In people with diabetes or high blood pressure it is checked routinely, and a persistently raised value usually prompts kidney-protective steps such as tighter blood-pressure and glucose control and specific medicines. Because a single raised result can come from a passing cause like infection, fever, exercise or menstrual blood, it is normally confirmed on one or two repeat samples before conclusions are drawn. A very high ratio, or a rising trend, warrants closer assessment. Mediora.AI shows UACR alongside creatinine, eGFR and urine protein so the early-kidney-damage pattern is visible over time; interpreting it and deciding on treatment belongs with your doctor.