Urine Protein

Alternate Names
protein in urine

Definition of Urine Protein

A urine protein test is used to detect the presence of protein in a person's urine. Normally, protein is not excreted in urine because the protein molecules are too large to pass through the filtering membranes in the kidneys (called glomeruli). If these filtering structures are damaged, protein escapes inappropriately. The presence of protein in the urine is an important indicator of kidney disease.

Who is a candidate for the test?

A test for protein in urine is done when a person is suspected of having:

• kidney problems with high blood pressure
• any kidney disease
• diabetes
• multiple myeloma, a tumor in the blood and bone marrow

Pregnant women are routinely tested for protein in the urine during prenatal visits to the healthcare provider. Protein in the urine during pregnancy may indicate preeclampsia, a serious condition that can cause high blood pressure and seizures in the mother. For insurance or other physicals like when starting a new job

How is the test performed?

There are 4 ways to check for urine protein:

• a urinalysis by a stick put into the urine sample,
• a random urine specimen that looks for minute amounts of protein (called "micro"albumin testing),
• a random urine specimen that looks for large amount of protein in the urine ("macro"albumin), and

• by 24 hour urine collections.

For the urinalysis or spot testing, a person is asked to supply a single, small urine sample.

First, the area around the urethra should be washed. Then, the person should:

• start urinating in the toilet
• catch a sample of urine in the container
• finish urinating in the toilet

The container should be covered and delivered to the health care provider for testing. The sample is usually the first urine of the day. Sometimes a 24-hour urine collection is needed for more accurate results. In this process, a person collects all the urine he or she voids during an entire 24-hour period.

In general, this schedule is followed:

• Day 1: The patient urinates upon arising as usual and discards that urine For example, at 7 a.m. on Monday). Then, the person collects all urine produced for the next 24 hours in a special container.
• Day 2: First thing the follwing morning (for example 7 a.m. Tuesday morning), the person collects the morning urine again in the container. Then the person covers the container and refrigerates it until it can be taken to the healthcare provider or assigned laboratory.

Often, urinary protein and several other substances are measured at the same time in a screening test known as urinalysis.

What is involved in preparation for the test?

A person should request specific instructions from his or her health care provider.

What do the test results mean?

Normally, there should be no protein detected in the urine. The presence of protein may indicate:

• kidney disease
• kidney injury from any cause including high blood pressure
• early kidney or blood vessel injury in diabetes ("micro"albumin)
• preeclampsia of pregnancy