Uacr Assessment Tool — Free nephrology Risk Score Calculator

How it Works

Formula

UACR = Urine Albumin (mg/L) / Urine Creatinine (g/L) Expressed as mg/g or mg/mmol

KDIGO Albuminuria Categories

A1 — Normal to Mildly Increased	< 30 mg/g
A2 — Moderately Increased	30–300 mg/g
A3 — Severely Increased	> 300 mg/g

Physiological Rationale

Albumin is a large, negatively charged protein that is normally excluded from the glomerular filtrate by charge- and size-selective barriers. A rise in UACR reflects injury to the podocytes, the glomerular basement membrane, or the endothelial glycocalyx — all signs of microvascular damage that frequently precede a rise in serum creatinine by years.

Clinical Pearls

Cardiovascular Risk Link

Albuminuria is an independent predictor of myocardial infarction, stroke, and all-cause mortality, even at UACR levels within the A1 range (< 30 mg/g). It is classified as a cardiovascular risk-enhancing factor by the ACC/AHA 2022 guidelines.

Measurement Pearls

Confirm abnormal UACR over at least 2 out of 3 tests over 3 months before classifying as CKD.

First-morning void is the preferred sample to eliminate orthostatic proteinuria.

Avoid testing within 24 hours of vigorous exercise, fever, or urinary tract infection.

Conditions That Falsely Elevate UACR

Acute febrile illness

Vigorous exercise within 24 hours

Menstrual contamination

Urinary tract infection (UTI)

Uncontrolled hypertension or heart failure

Next Steps

Management by Category

A1 (< 30): Normal	Annual screen if DM/HTN present. No pharmacological action.
A2 (30–300): Moderate	Initiate ACEi/ARB. Target ≥ 50% UACR reduction. SGLT2i.
A3 (> 300): Severe	Nephrology referral. Renal biopsy consideration. Intensify RAAS blockade.

Complementary Tools

eGFR (CKD-EPI)

CKD Stage (KDIGO)

KFRE — Kidney Failure Risk Equation

The Evidence

Foundational Reference

Proteinuria as a surrogate outcome in CKD: report of a scientific workshop sponsored by the NKF and the FDA.

Levey AS et al. • Am J Kidney Dis.. 2009;54(2):205-226. Established albuminuria as both a diagnostic marker and a treatment response surrogate.

Guideline Endorsement

KDIGO 2024 and ADA 2024 Standards of Care both mandate annual UACR screening for all patients with T1DM (after 5 years), all T2DM patients at diagnosis, and all patients with hypertension.

Origins & History

Microalbuminuria: A Paradigm Shift

The concept of "microalbuminuria" — albumin loss below the detection threshold of standard dipstick urinalysis — was first described in the 1980s by Danish researcher Hans-Henrik Parving. His work demonstrated that even trace amounts of albumin in the urine predicted diabetic nephropathy progression, fundamentally changing how clinicians screen for kidney complications.

UACR

When to Use

When to Use

Why UACR Over UPCR?

How it Works

Formula

KDIGO Albuminuria Categories

Physiological Rationale

Clinical Pearls

Cardiovascular Risk Link

Measurement Pearls

Conditions That Falsely Elevate UACR

Next Steps

Management by Category

Complementary Tools

The Evidence

Foundational Reference

Proteinuria as a surrogate outcome in CKD: report of a scientific workshop sponsored by the NKF and the FDA.

Guideline Endorsement

Origins & History

Microalbuminuria: A Paradigm Shift

In Recent Clinical News

UACR

When to Use

When to Use

Why UACR Over UPCR?

How it Works

Formula

KDIGO Albuminuria Categories

Physiological Rationale

Clinical Pearls

Cardiovascular Risk Link

Measurement Pearls

Conditions That Falsely Elevate UACR

Next Steps

Management by Category

Complementary Tools

The Evidence

Foundational Reference

Proteinuria as a surrogate outcome in CKD: report of a scientific workshop sponsored by the NKF and the FDA.

Guideline Endorsement

Origins & History

Microalbuminuria: A Paradigm Shift

In Recent Clinical News