Albumin (urine)


Alternative names, keywords

albumin:creatinine ratio, ACR, "microalbumin"

Samples required

5 mL plain urine

Test indications


Factors affecting test performance/ results

False positives include benign orthostatic proteinuria, symptomatic UTI, and menstrual contamination.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

< 3 mg/mmol creatinine.

An ACR between 3 mg/mmol and 70 mg/mmol should be repeated on an early morning sample to confirm the result. A repeat sample is not needed if the initial ACR is 70 mg/mmol or more.

A confirmed ACR of 3 mg/mmol or indicates clinically important proteinuria.

KDIGO ACR classification:

less than 3 mg/mmol KDIGO ACR category A1

3 - 30mg/mmol, KDIGO ACR category A2                  

over 30mg/mmol, KDIGO ACR category A3

Source: NICE NG203 Chronic kidney disease: assessment and management.

Turnaround time

Same day (within 2h if urgent)


Biochemistry (Automation)