ADAM Health Encyclopedia

Protein - urine

Definition

A protein urine test measures the amount of proteins, such as albumin, found in a urine sample.

A blood test may also be done to measure the level of albumin. See: Serum albumin

Alternative Names

Why the Test is Performed

This test is most often performed when kidney disease is suspected. It may be used as a screening test.

Normally, protein is not found in urine when a routine dipstick test is performed. This is because the kidney is supposed to keep large molecules, such as protein, in the blood and only filter out smaller impurities. Even if small amounts of protein do get through, they are normally reabsorbed by the body and used as a source of energy.

Some proteins will appear in the urine if the levels of protein in blood become high, even when the kidney is functioning properly.

If the kidney is diseased, protein will appear in the urine even if blood levels are normal.

How the Test is Performed

Urine protein may be tested using a random sample of urine and a dipstick test, or it may require a 24-hour urine sample. See: 24-hour urine protein.

How to Prepare for the Test

Your health care provider may tell you to temporarily stop taking any drugs that can interfere with test results.

Drugs that can affect measurements include:

• Acetazolamide
• Aminoglycosides
• Amphotericin B
• Cephalosporins
• Colistin
• Griseofulvin
• Lithium
• Methicillin
• Nafcillin
• Kidney damaging drugs
• Oxacillin
• Penicillamine
• Penicillin G
• Phenazopyridine
• Polymyxin B
• Salicylates
• Sulfonamides
• Tolbutamide
• Viomycin

The following may also interfere with test results.

• Severe emotional stress
• Strenuous exercise
• Receiving a special dye (contrast media) for a radiology exam within 3 days before the urine test
• Urine contaminated with vaginal secretions

How the Test Will Feel

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

Risks

There are no risks.

Normal Results

For a random urine sample, the normal values are approximately 0 to 8 mg/dL.

For a 24-hour urine collection, the normal value is less than 150 mg per 24 hours.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may be due to:

• Amyloidosis
• Bacterial pyelonephritis
• Bladder tumor
• Congestive heart failure
• Diabetic nephropathy
• Glomerulonephritis
• Goodpasture syndrome
• Heavy metal poisoning
• Lupus erythematosus
• Malignant hypertension
• Multiple myeloma
• Nephrotic syndrome
• Nephrotoxic drug therapy
• Polycystic kidney disease
• Preeclampsia

• Acute nephritic syndrome
• Complicated UTI (pyelonephritis)
• Eclampsia
• Hemolytic-uremic syndrome (HUS)
• Interstitial nephritis
• Medullary cystic disease
• Membranoproliferative GN I
• Membranoproliferative GN II
• Membranous nephropathy
• Necrotizing vasculitis
• Post-streptococcal GN
• Rapidly progressive (crescentic) glomerulonephritis
• Reflux nephropathy
• Renal vein thrombosis
• Rocky mountain spotted fever