The Effects of Protein on the Kidney

The kidney acts as a filter that prevents too much protein from being expelled through urine. When urine contains an abnormal amount of protein, it is a condition called proteinuria. This can be an indication of a "silent" kidney disease.

Facts

• Early detection and treatment of proteinuria may reduce the progression of kidney disease, whcih can lead to chronic kidney disease and possibly end-stage renal disease, whereby the kidneys fail completely.

Symptoms

• In proteinuria, no signs or symptoms are present in the early stages. But as the condition progresses, edema (swelling) in the face, abdomen, feet and hands may occur. Urine that appears foamy may contain large amounts of protein.

Diagnosis

• Urinalysis is used to determine and measure the amount of albumin (main protein in the blood) in the urine and compare it to the amount of creatinine (waste product of normal muscle breakdown) in the urine. A sample containing more than 30 mg of albumin for each gram of creatinine is an initial sign of declining kidney function.

Risks

• People with diabetes, hypertension or a family history of kidney disease are at risk for proteinuria. In the United States, the leading cause of end-stage renal disease is diabetes. If hypertension is not controlled, it can progress to kidney failure.

Warning

• Regular use of over-the-counter pain medicines like ibuprofen and the abuse of street drugs like heroin can cause protein leaks and kidney damage. AIDS and HIV are also common causes of heavy protein losses in the urine, and kidney failure.