A protein urine test measures the amount of protein present in urine. Normally, healthy people don’t have protein in their urine. However, protein may be excreted in the urine when the kidneys aren’t working properly or when high levels of certain proteins are present in the bloodstream.
Your doctor may collect a urine test for protein as a random one-time sample, or every time you urinate over a 24-period. A urine protein test is also called urine albumin test or proteinuria.
Reasons for Testing
Your doctor may order this test if they suspect a problem with your kidneys. They also may order the test:
- to see if a kidney condition is responding to treatment
- if you have symptoms of a urinary tract infection (UTI)
- as part of a routine urinalysis
A small amount of protein in the urine is normally not a problem. However, larger levels of protein in the urine may be caused by:
- kidney infection
- amyloidosis (a build-up of protein in the body’s tissues)
- drugs that damage the kidneys (such as NSAIDs, antimicrobials, diuretics, and chemotherapy drugs)
- hypertension (high blood pressure)
- preeclampsia (high blood pressure in pregnant women)
- heavy metal poisoning
- polycystic kidney disease
- congestive heart failure
- glomerulonephritis (a kidney disease that causes kidney damage)
- systemic lupus erythematosus (an autoimmune disease)
- Goodpasture syndrome (an autoimmune disease)
- multiple myeloma (a type of cancer affecting bone marrow)
- bladder tumor or cancer
Certain people are more at risk for developing kidney problems. Your doctor may order regular protein urine testing to screen for kidney problems if you have one or more risk factors.
Risk factors include:
- having a chronic condition such as diabetes or hypertension
- having a family history of kidney disease
- being of African American, American Indian, Hispanic American, or Pacific Islander descent
- being overweight
- being an older age
It’s important your doctor knows all the medications you’re currently taking, including over-the-counter and prescription medications. Certain medications can affect the level of protein in your urine, so your doctor may ask you to stop taking a certain medication or to change your dose before the test.
Medications that affect protein levels in the urine include:
- antibiotics (including aminoglycosides, cephalosporins, penicillins, polymyxin B, and sulfonamides)
- antifungal medications (including amphotericin B and griseofulvin)
- penicillamine (a medication used to treat rheumatoid arthritis)
- phenazopyridine (a medication used for urinary tract pain)
- salicylates (medications used to treat arthritis)
- tolbutamide (a medication used for diabetes)
It’s important that you’re well-hydrated before giving your urine sample. This makes giving the urine sample easier and prevents dehydration, which can affect test results.
Avoid strenuous exercise before your test, as this can also affect the amount of protein in your urine. You should also wait to take a protein urine test at least three days after taking a radioactive test that used contrast dye. The contrast dye used in the test is secreted in your urine and can affect results.
Random One-Time Sample
A random, one-time sample is one way protein is tested in the urine. This may also be called a dipstick test. You may give your sample in your doctor’s office, a medical laboratory, or at home.
You’ll be given a sterile container with a cap and a towellette or swab to clean around your genitals. To begin, wash your hands well and take the cap off the collection container. Do not touch the inside of the container or the cap with your fingers, or you may contaminate the sample.
Clean around your urethra using the wipe or swab. Next, begin urinating into the toilet for several seconds. Stop the flow of urine, position the collection cup under you, and begin collecting urine midstream. Don’t let the container touch your body, or you may contaminate the sample. You should collect about 2 ounces of urine.
When you’re finished collecting the midstream sample, continue urinating into the toilet. Replace the cap on the container and follow the instructions for returning it to your doctor or medical lab. If you’re unable to return the sample within one hour of collecting it, place the sample in the refrigerator.
Your doctor may order a 24-hour collection if there was protein in your one-time urine sample. For this test, you’ll be given a large collection container and several cleansing wipes. Do not collect your first urination of the day. However, record the time of your first urination because it will begin the 24-hour-collection period.
For the next 24 hours, collect all your urine in the collection cup. Be sure to clean around your urethra before urinating and do not touch the collection cup to your genitals. Store the sample in your refrigerator between collections. When the 24-hour period is over, follow the instructions you were given for returning the sample.
Your doctor will evaluate your urine sample for protein. They may want to schedule another protein urine test if your results show you have high levels of protein in your urine. They may also want to order other lab tests or physical examinations.