Urine Protein Test

This is a test used to detect excessive protein escaping into the urine, to help evaluate and monitor kidney function, and to detect kidney damage. Proteins usually are not found in the urine. The kidneys (two organs found in the back at the bottom of the rib cage) filter the blood, removing wastes and excreting them out of the body in the form of urine. When the kidneys are functioning normally, they retain or reabsorb filtered protein molecules and return them to the blood. However, if the kidneys are damaged, they become less effective at filtering, and detectible amounts of protein begin to find their way into the urine. Often, it is the smaller albumin molecules that are detected first. If the damage continues, the amount of protein in the urine increases, and globulins may also begin to be lost.

Proteinuria (protein in the urine) is frequently seen in chronic diseases, such as diabetes and hypertension, with increasing amounts of protein in the urine reflecting increasing kidney damage. With early kidney damage, the patient is often asymptomatic. As damage progresses or if protein loss is severe, the patient may have symptoms such as edema (swelling and fluid retention), shortness of breath, nausea, and fatigue. Excess protein production, such as may be seen with multiple myeloma, can also lead to proteinuria.


A random urine sample is collected in a clean container. For a 24-hour urine collection, all of the urine is collected for a 24-hour period. It is important that the sample be refrigerated during this time period. There should be no preservative in the container.


  • 0-8 mg/dL

  • 50-80 mg/24 hr (at rest)

  • Less than 250 mg/24 hr (during exercise)




