Skip to main content

Albumin and protein in urine

Albumin is the main protein found in the blood. The kidneys are the organs that filter the blood. They use several mechanisms to prevent protein from being excreted in the urine. Therefore, only tiny amounts of albumin and other proteins should be present in the urine. However, when the kidneys aren't functioning properly, such as in people with diabetes or high blood pressure, more albumin may pass into the urine. Before the issue becomes serious, there is a stage called microalbuminuria, where a small but significant amount of albumin is found in the urine. This is a warning sign that the kidneys may need attention.

Several tests are used to measure albumin and protein in the urine. Here are some examples:

  • Urine dipstick test:
    • A urine dipstick detects the presence of protein (albumin) in a urine sample.
    • It does not detect small amounts of albumin in the urine.
  • Urine sample test:
    • Single or spot urine collection: Test performed on urine from a single urination, often the first urine passed in the morning.
    • 24-hour urine collection: Test performed on urine produced over a 24-hour period. Most accurate result for measuring albumin in urine.
    • Test performed on urine collected over a specific period of time.
    • Urine sample tests can be used to detect abnormally high levels of albumin in the urine (e.g., microalbuminuria).
  • Albumin-creatinine ratio (ACR):
    • Calculation based on urine albumin and creatinine levels.
    • Used to diagnose chronic diabetic nephropathy, among other conditions.
What is the purpose of this test?
  • To detect early signs of kidney disease, often associated with diabetes or high blood pressure.
  • To assess kidney health by checking for the presence of proteins in the urine.
How to prepare?
  • Avoid strenuous physical activity for 24 hours before and during the collection.
  • No other preparation is required.
Reference values*
  • Urine dipstick test
    • A positive result indicates the presence of a significant amount of protein in the urine.
    • A negative result does not necessarily mean that there is no protein in the urine. This test is not sensitive enough to detect small amounts of protein.
  • Albumin in urine collected over 24 hours
    • Normal: < 30="" mg/24="">
    • Microalbuminuria: 30 - 300 mg/24 h
    • Macroalbuminuria (proteinuria): > 300 mg/24 h
  • Albumin in urine from single or spot urine collection
    • Normal: < 20="">
  • Albumin-creatinine ratio (ACR)
    • Normal: < 2.0="" mg/mmol="">
    • Microalbuminuria: Repeated results between 2.0 and 20 mg/mmol creatinine.
    • Macroalbuminuria (proteinuria): Repeated results above 20 mg/mmol creatinine.
Associated tests Several associated tests, including:
How is it done?
  • Urinalysis and single or spot urine collection:
    • Clean the skin around the opening of the urethra.
    • Urinate into the toilet for a few seconds, then stop.
    • Hold the container in position and urinate directly into it (collect approx. 60 mL of urine).
  • Urine collection over 24 hours or over a specific period of time:
    • Upon waking, empty the bladder without collecting this urine.
    • Note the start time for the collection period.
    • Collect all urine produced over the specified time period in a small, clean container. Then pour the urine into the large container.
    • Keep the collected urine refrigerated for the duration of the collection period.
    • Empty the bladder for the last time at or just before the end of the collection period.
    • Note the end time of the collection period.
How long before I get the results? Results are usually ready in a day. It may take longer to receive your results.
* These values are presented for information purposes only. As different laboratories may have different target values, the lab report usually specifies the values used for the test. It should also be noted that test results must be interpreted based on factors such as age, sex, and health condition. Values outside of this range may be considered normal for some individuals.

What does an abnormal test result mean?

High values of albumin or other proteins:

  • Kidney damage
  • Inflammatory issue (e.g., lupus)
  • Bone marrow issue (e.g., multiple myeloma)

Medications that may affect test results

The use of certain medications can influence test results. Here are a few examples:

  • Non-steroidal anti-inflammatory drugs (e.g., ibuprofen, naproxen)
  • Certain antibiotics (e.g., cephalosporins and penicillins)
  • Lithium

Factors that can interfere with test accuracy

Certain temporary situations can cause a small amount of protein to be excreted in the urine. The following should be taken into account when interpreting test results:

  • Vigorous physical activity
  • Fever
  • Pregnancy
  • Stress
  • Infections (e.g., urinary tract infections)
  • Dehydration

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.

© Copyright Vigilance Santé

The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.

Find a Pharmacy

Newsletter Signup
Tips from your personal pharmacist, straight to your inbox.
Expect up-to-date health and lifestyle advice, special promotions, and more!