24-hour urine protein

Definition

24-hour urine protein measures the amount of protein released in urine over a 24-hour period.

Alternative Names

Urine protein - 24 hour; Chronic kidney disease - urine protein; Kidney failure - urine protein

How the Test is Performed

A 24-hour urine sample is needed:

• On day 1, urinate into the toilet when you get up in the morning.
• Afterward, collect all urine in a special container for the next 24 hours.
• On day 2, urinate into the container when you get up in the morning.
• Cap the container. Keep it in the refrigerator or a cool place during the collection period.
• Label the container with your name, the date, the time of completion, and return it as instructed.

For an infant, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, place the entire penis in the bag and attach the adhesive to the skin. For females, place the bag over the labia. Diaper as usual over the secured bag.

This procedure may take a couple of attempts. Active infants can move the bag, causing the urine to be absorbed by the diaper. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. Drain the urine from the bag into the container provided by your health care provider.

Deliver it to the lab or your provider as soon as possible upon completion.

How to Prepare for the Test

Your provider will tell you, if needed, to stop taking any medicines that may interfere with the test results.

A number of medicines can change the test results. Make sure your provider knows about all medicines, herbs, vitamins, and supplements you are taking.

The following may also affect test results:

• A lack of fluid (dehydration)
• Any type of x-ray exam with dye (contrast material) within 3 days before the urine test
• Fluid from the vagina that gets into the urine
• Severe emotional stress
• Strenuous exercise
• Urinary tract infection

How the Test will Feel

The test involves only normal urination, and there is no discomfort.

Why the Test is Performed

Your provider may order this test if blood, urine, or imaging tests find signs of damage to kidney function.

To avoid a 24-hour urine collection, your provider may be able to order a test that is done on just one urine sample (protein-to-creatinine ratio).

Normal Results

The normal value is less than 100 milligrams per day or less than 10 milligrams per deciliter of urine.

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may be due to:

• A group of diseases in which a protein called amyloid builds up in the organs and tissues (amyloidosis)
• Bladder tumor
• Heart failure
• High blood pressure during pregnancy (preeclampsia)
• Kidney disease caused by diabetes, high blood pressure, autoimmune disorders, a blockage in the kidney system, certain medicines, toxins, a blockage of blood vessels, or other causes
• Multiple myeloma

Healthy people may have higher than normal urine protein level after strenuous exercise or when they are dehydrated. Some foods may affect urine protein levels.

Risks

The test involves normal urination. There are no risks.

References

Chau K, Hutton H, Levin A. Laboratory assessment of kidney disease: glomerular filtration rate, urinalysis, and proteinuria. In: Skorecki K, Chertow GM, Marsden PA, Taal MW, Yu ASL, eds. Brenner and Rector's The Kidney. 10th ed. Philadelphia, PA: Elsevier; 2016:chap 26.

Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 114.