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Microalbumin18hurmrate

Published: July 31, 2026Updated: August 17, 2026

This test measures small amounts of protein (albumin) in your urine to check for early kidney damage.

Quick summary

{"Microalbuminuria is an early sign of kidney damage, often seen in diabetes patients","The test requires collecting all urine over an 18-hour period","Results help doctors detect kidney problems before they become serious","Normal results: less than 30 mg per 24 hours","Early treatment can prevent kidney disease from worsening"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
63474-1
Short code
MAU18
Synonyms
Microalbumin 18h Ur-mRate
Category
chemistry
Sample
urine
Container
Sterile urine container (24-hour collection container with preservative if needed)
Units
not specified
Ref low
0
Ref high
20
Critical range
1.5 not specified – —
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
detection-limit-mg-l
CPT
82043
SNOMED
27516006
Specimen volume
Aliquot of 10-20 mL from well-mixed 18-hour collection
Stability
Room temperature: 24-48 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C): 30 days
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
24–72 hours
Order
routine

What is this test?

The microalbumin test measures tiny amounts of a protein called albumin in your urine. Normally, healthy kidneys filter waste from your blood while keeping important proteins like albumin in your body. When kidneys are damaged, they may leak small amounts of albumin into your urine—this is called microalbuminuria. This test uses urine collected over 18 hours to get a more accurate measurement than a single urine sample.

How is the sample collected?

You will collect all your urine over an 18-hour period into a special container provided by your healthcare provider. Typically, you start collecting after your first morning urine and continue until the same time the next day. It's important to keep the container refrigerated or in a cool place during collection. Record the exact start and end times of your collection.

What do the results mean?

Results are usually expressed as milligrams (mg) of albumin per 24 hours: Normal is less than 30 mg/24 hours (or less than 20 mcg/min). Microalbuminuria (early kidney damage) is 30-300 mg/24 hours. Overt nephropathy (significant kidney disease) is greater than 300 mg/24 hours. Your doctor will interpret your results based on your overall health and any existing conditions.

How to prepare for the test?

No special fasting is required. However, avoid strenuous exercise and heavy physical activity during the collection period, as these can temporarily increase albumin in urine. Inform your doctor about all medications you're taking, as some drugs can affect test results. Follow the specific instructions provided by your healthcare facility carefully.

Reference range

0-20 mcg/minnot specified

Specimen: urine

Complete 18-hour timed urine collection required; empty bladder at start time and collect all urine thereafter. Avoid strenuous exercise before/during collection. No fasting needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Does the 18-hour urine collection need to be exact?
Try to be as accurate as possible with timing, but a small variation (15-30 minutes) usually won't significantly affect results. Record your exact start and end times. If you miss a collection or spill some urine, inform your healthcare provider—they may need to repeat the test.
Can I collect urine while on my period?
Ideally, urine collection should be done when you are not menstruating, as blood can contaminate the sample and affect results. If this isn't possible, discuss it with your doctor—they may advise using a tampon during collection.
What happens if my results show microalbuminuria?
If your results show microalbuminuria, your doctor will likely recommend: tighter blood sugar control (if you have diabetes), blood pressure management (often with ACE inhibitors or ARBs), lifestyle changes including diet and exercise, and regular monitoring of kidney function. Early intervention is very effective at preventing further kidney damage.
Is this test painful or risky?
No—this is a non-invasive test that only involves collecting urine. There are no risks or side effects. The main challenge is following the 18-hour collection instructions carefully to ensure accurate results.
How long does it take to get results?
Results are typically available within 1-3 days, depending on the laboratory. Your healthcare provider will contact you with results or discuss them at your next appointment.
  1. 1
    National Kidney Foundation - MicroalbuminuriaSource
  2. 2
    American Diabetes Association - Standards of CareSource
  3. 3
    MedlinePlus - Urine AlbuminSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy