Protein - urine
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
Urine protein; Albumin - urine; Urine albumin; Proteinuria; Albuminuria
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:
- Amphotericin B
- Kidney damaging drugs
- Penicillin G
- Polymyxin B
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
- Urinary tract infection
- Urine contaminated with vaginal secretions
How the test will feel
The test only involves normal urination, and there is no discomfort.
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.
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:
- Bladder tumor
- Congestive heart failure
- Diabetic nephropathy
- Goodpasture syndrome
- Heavy metal poisoning
- Lupus erythematosus
- Malignant hypertension
- Multiple myeloma
- Nephrotic syndrome
- Damage to the kidneys from certain drugs (nephrotoxic drugs)
- Polycystic kidney disease
- Urinary tract infection
Additional conditions under which the test may be performed:
- Acute nephritic syndrome
- Body-wide (systemic) infection
- Hemolytic-uremic syndrome (HUS)
- Interstitial nephritis
- Medullary cystic kidney disease
- Membranoproliferative GN I and GN II
- Membranous nephropathy
- Necrotizing vasculitis
- Post-streptococcal glomerulonephritis
- Rapidly progressive (crescentic) glomerulonephritis
- Reflux nephropathy
- Renal vein thrombosis
What the risks are
There are no risks.
Bazari H. Approach to the patient with renal disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 115.
Reviewed 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.