24-hour 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.
• Afterwards, 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 -- lively 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 laboratory or your health care provider as soon as possible upon completion.

How to Prepare for the Test

Your health care provider will instruct you, if necessary, to stop taking any drugs that may interfere with the test results.

Drugs that can affect measurements include:

• Acetazolamide
• Aminoglycosides
• Amphotericin B
• Cephalosporins
• Colistin
• Griseofulvin
• Lithium
• Methicillin
• Nafcillin
• Nephrotoxic drugs (kidney damaging drugs)
• Oxacillin
• Penicillamine
• Penicillin G
• Phenazopyridine
• Polymyxin B
• Salicylates
• Sulfonamides
• Tolbutamide

The following may also interfere with test results.

• Dehydration
• Dye (contrast media) for a radiology exam within 3 days before the urine test
• Severe emotional stress
• Strenuous exercise
• Urinary tract infection
• Urine contaminated with vaginal secretions

How the Test Will Feel

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

Why the Test is Performed

Your doctor may order this test if you have signs or symptoms of glomerular disease, such as nephrotic syndrome, or another condition that may affect kidney function.

Normal Results

The normal value is less than 80 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 doctor about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may be due to:

• Amyloidosis
• Bladder tumor
• Congestive heart failure
• Dehydration
• Diabetic nephropathy
• Glomerulonephritis
• Goodpasture syndrome
• Heavy metal poisoning
• Malignant hypertension
• Multiple myeloma
• Nephrotic syndrome
• Polycystic kidney disease
• Preeclampsia and eclampsia
• Systemic lupus erythematosus
• Urinary tract infection
• Use of kidney damaging drugs
• Waldenstrom's macroglobulinemia

Additional conditions under which the test may be performed:

• Acute nephritic syndrome
• Bodywide (systemic) infection (sepsis)
• Hemolytic-uremic syndrome (HUS)
• Interstitial nephritis
• Medullary cystic kidney disease
• Membranoproliferative GN I and GN II
• Membranous nephropathy
• Necrotizing vasculitis
• Reflux nephropathy
• Renal vein thrombosis

Healthy people may have higher than normal urine protein levels after strenuous exercise or with dehydration. Some foods may affect urine protein levels.

Risks

The test involves normal urination and there are no risks.

Considerations

Sometimes, in order to avoid the inconvenience and possible inaccuracy of a 24-hour urine collection, your doctor may order a test done on just one urine sample, called the protein-to-creatinine ratio.

Alternative Names

Urine protein - 24 hour

References

Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 116.

Update Date: 8/21/2011

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.