Edition: June 2003 - Vol 11 Number 06
Although they are no larger than an average-sized fist, the kidneys process as much as 50 gallons of blood daily, removing waste, toxins and excess water through about a half-gallon of urine, according to Harvard Medical School in Boston. The two bean-shaped organs sit below the rib cage, on either side of the spine.
By removing waste products and toxins, the kidneys prevent these materials from accumulating to dangerous levels in the blood. Similarly, if the kidneys did not remove excess water and it accumulated in the blood, blood pressure would rise, the heart would become overloaded and blood chemicals would become imbalanced and diluted. Flexible organs that they are, the kidneys can also conserve water when levels are low, as in dehydration.
The kidneys rid the blood of excess chemicals ? including electrolytes, acids and bases ? and conserve chemicals when levels are low. After the blood is cleansed, it exits through the renal veins and returns to circulation.
Chronic and Acute Kidney Disease
When the kidneys are unable to function properly and no longer filter enough wastes from the blood, kidney disease ? or chronic renal failure ? occurs. A number of factors contribute to renal failure, including diabetes, cancer, high blood pressure, heredity, drug side effects, kidney stone blockage or prostate problems, according to Abbott Laboratories. An individual may lose as much as 80 percent of his or her kidney function before symptoms of kidney disease surface. Symptoms include the:
? Decreased appetite
? Increased urination
? Increased thirst
? Pale skin
? High blood pressure
? Growth failure in children
? Bone damage in adults.
Acute renal failure ? which may result from a sudden illness, a medication or a medical condition that causes a severe drop in blood pressure, interruption in blood flow, heart attack, urine blockage or damage to kidney cells ? can resolve itself. Chronic renal failure, on the other hand, is a lifelong problem that can worsen over time, leading to end-stage renal failure.
End-Stage Renal Failure
In end-stage renal failure, the kidneys no longer act as life-sustaining organs. Patients require treatment with dialysis and, inevitably, a kidney transplant. The most common causes of end-stage renal failure are:
? Rheumatic diseases (such as lupus)
? Genetic disorders (such as polycystic kidney disease)
? Exposure to toxic drugs, such as certain antibiotics, chemotherapy, contrast dyes and pain relievers.
Kidney disease patients? blood tests generally indicate excessive levels of creatinine and blood urea nitrogen, since the kidneys no longer can remove these chemicals from the blood. In end-stage renal failure, dialysis is prescribed when the following problems arise:
? Pericarditis (inflammation of the heart lining)
? Congestive heart failure
? Severely elevated blood pressure that cannot be controlled by medication
? Bleeding related to renal failure
? Severe, continuous nausea and vomiting
? Severe abnormalities in blood tests.
As many as 40 percent of diabetes type 1 patients commonly develop kidney disease, referred to as diabetic nephropathy. In fact, over a third of the 50,000 patients diagnosed with end-stage renal disease are diabetic. Early symptoms of diabetic nephropathy are ankle swelling and fatigue, although symptoms generally aren?t apparent until the disease is well-established. Later symptoms include extreme fatigue, nausea, vomiting and decreased urine production. One of the first indications of kidney damage is the microscopic detection of the protein microalbuminuria in the urine. Small amounts of this protein precede major kidney damage by five to 10 years.
Diabetics can help prevent kidney disease by maintaining control over their blood sugar levels. A low-protein diet also is believed to inhibit the development of kidney disease, as is the reduction of lipid levels through diet, exercise and medication.
Over 20 million Americans have chronic kidney disease and another 20 million are at increased risk, according to the National Kidney Foundation. More than 70,000 Americans die each year from the disease, which remains one of the most costly illnesses in this country. The National Kidney Foundation also notes the following:
? Over 378,000 Americans require dialysis or a kidney transplant to stay alive.
? More than 50,000 patients are wait-listed for kidney transplants. Due to a shortage of acceptable organ donors, however, only 14,000 will receive transplants this year.
? The leading cause of chronic kidney failure is diabetes mellitus (type 2 adult onset). It accounts for 44 percent of new cases annually and 35 percent of all cases in the United States.
? Poorly controlled high blood pressure is the second leading cause of chronic kidney failure in the United States.
? Kidney and urologic disease are a major cause of work-loss among Americans.
? Kidney stones alone account for over 1 million physician visits and more than 300,000 hospitalizations each year.