The kidneys are the organs in charge of filtering the blood from toxic substances and excreting them from the body in the urine. The kidneys also help in the body's regulation of fluids and electrolytes, such as sodium and potassium. Proteins are usually too big for the kidneys to filter them out, therefore remaining in the body's blood circulation. Occasionally the kidneys are damaged, and allow for the loss of large amounts of protein in the urine, a condition called proteinuria.
Causes
There are many causes of proteinuria, since the presence of protein in the urine is a sign of chronic kidney disease. According to the National Kidney and Urologic Diseases Information Clearinghouse, diabetes is the leading cause of end-stage renal disease, a significant risk factor for the loss of protein in the urine. Another cause of kidney disease and proteinuria is poorly controlled, chronic hypertension, or high blood pressure.
Effects
Proteins are electrically charged molecules. As such, they help keep fluids inside blood vessels from leaking into the surrounding tissues. When proteins are lost on in the urine, fluids leaks out of the vessels, causing edema, or swelling of the hands, feet, abdomen or face. Large amounts of proteins in the urine can make it look frothy or foamy.
Diagnosis
Routine urinalysis can detect the presence of proteins in the urine, but not the amount of protein present. According to the Merck Manual, a 24-hour urine collection is necessary to assess the amount of protein excreted in the urine. Other tests are important to determine the cause for the loss of protein from the kidneys. These tests include a BUN, or blood urea nitrogen, and a creatinine test, both of which evaluate kidney function. If the cause of the proteinuria is not evident, a kidney biopsy may offer a definitive answer.
Treatment
The treatment of protein loss in the urine is aimed at correcting to the underlying cause. Diabetes and hypertension need to be controlled, but by the time there is end stage renal disease any changes in lifestyle or medications may not be sufficient. People with swelling and edema may benefit from intravenous infusions of albumin, the main protein in the blood, and diuretics, which are medicines that help mobilize excess fluid into the urine for excretion.
Warning
Apart from controlling hypertension and diabetes, people with proteinuria can benefit from having a low salt diet. This helps improve high blood pressure and decreases the amount of fluid retention and edema. Patients with end stage renal disease may need dialysis or a renal transplant to prevent further loss of protein in the urine.
Member Comments