Microalbuminuria
Microalbuminuria is a small amount of the protein albumin leaking into the urine - the earliest sign that obesity, high blood pressure or diabetes is straining the kidney filters, and it is detected with a simple urine test.
Plain English
Patient-Friendly Explanation
Healthy kidneys filter blood like a fine sieve: waste passes into the urine while protein stays in the bloodstream. When the tiny filtering units are under pressure - from high blood pressure, high blood sugar, or the raised filtration pressure that comes with excess weight - small amounts of the protein albumin slip through. That leakage, called microalbuminuria or moderately increased albuminuria, is measured with a urine albumin-to-creatinine ratio rather than a dipstick, since dipsticks miss the low levels that matter most. There are no symptoms, which is the point of screening. It matters because it is both an early warning of kidney damage and a marker of higher risk of heart attack and stroke, and because it can be reversed: blood pressure control with the right medication, better blood sugar, less salt, stopping smoking and losing weight often bring the leakage back to normal. Anyone with diabetes, high blood pressure or obesity should have it checked at least once a year.
Medical
Clinical Definition
Albuminuria is staged by the urine albumin-to-creatinine ratio (UACR): A1 normal (<30 mg/g), A2 moderately increased, historically called microalbuminuria (30-300 mg/g, equivalent to 3-30 mg/mmol), and A3 severely increased (>300 mg/g). Confirmation requires two of three abnormal first-morning samples because exercise, fever, urinary infection and menstruation cause transient rises. In obesity, glomerular hyperfiltration and glomerular hypertension, RAAS activation, sympathetic overactivity and obesity-related glomerulopathy with podocyte injury underlie the leak; albuminuria frequently precedes any fall in eGFR, which is why it is the earlier marker. It independently predicts progression to chronic kidney disease and end-stage renal disease and cardiovascular mortality in diabetic and non-diabetic populations, and is included in KDIGO risk stratification together with eGFR. Management is by renin-angiotensin system blockade (ACE inhibitor or ARB), SGLT2 inhibitors in eligible patients, blood-pressure and glycaemic targets, sodium restriction, smoking cessation and weight reduction - regression of albuminuria correlates with slower loss of kidney function.
Key Insight
Why It Matters
This is the cheapest, quietest early-warning test we have for the kidneys, and it is not part of a standard health screening panel unless someone asks for it. If you have diabetes, high blood pressure or a raised waist, request a urine albumin-to-creatinine ratio once a year - a raised result is a signal to treat, not a diagnosis of kidney failure.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: September 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
