KIDNEYS: WHAT THEY DO

Your two kidneys keep your blood clean and chemically balanced. These bean-shaped organs (about the size of your fist) are located near the middle of your back, just below the rib cage. The kidneys have 3 functions:

to eliminate certain waste products from the body
to keep the right balance of chemicals in the body and
to release 3 hormones related to blood pressure, red blood cell production, and maintaining the body's calcium level

As "trash collectors," the kidneys filter about 200 quarts of blood everyday in order to sift out about 2 quarts of waste products and extra water. The waste and extra water become urine, which flows to your bladder through tubes called ureters. Your bladder stores urine until you go to the bathroom.

Normal waste products in the blood come from muscle and the food we eat. The body uses food as energy and to supply the building blocks for proteins and other substances. The body takes what it needs from the food and sends the waste to the blood. A build-up of waste products in the blood could damage the body. Through a filtering process, the kidneys regulate the body's level of chemicals like sodium, phosphorus, and potassium. They maintain the right balance necessary for life, because excess levels of certain chemicals can be harmful.

As the "watchdogs" of the body's internal environment, the kidneys do an effective job of retaining what is necessary and eliminating what is not necessary. As a result, we are able to eat a diet that varies greatly from day to day and from person to person without disturbing the internal chemical environment of the body.

In addition to removing wastes, the kidneys release 3 important hormones that stimulate the bones to make red blood cells, regulate blood pressure, and help maintain calcium for bones and for normal chemical balance in the body. Any changes of the hormonal functions of the kidneys may lead to high blood pressure, anemia, or disturbances of calcium metabolism.

The most common causes of kidney disease are diabetes and high blood pressure. A person may also be at risk for kidney disease if there is a family history of any kind of kidney problems. Most kidney diseases attack its filtering system. Injury or poisoning may cause rapid kidney damage. However, most kidney diseases destroy the filtering system so slowly and silently that it may take years or even decades for the damage to become apparent. It is not unusual for a person to lose 80 percent of his normal kidney function before any symptoms of illness appear. When there is 10 percent or less of normal kidney function, one cannot live long without some help for the kidneys, such as dialysis.

As the loss of kidney function progresses with kidney disease, eventually the accumulation of waste products causes symptoms such as:

loss of appetite
nausea and vomiting
urination that is either more often or less often
swelling or numbness of the hands or feet
drowsiness and trouble concentrating
skin darkening and
muscle cramps

A variety of blood, urine, or other tests are performed to determine the extent of any damage or kidney disease. Treatment may be as simple as making dietary changes, monitoring blood sugar and cholesterol levels, and controlling blood pressure. Advanced cases of kidney disease may require some form of regular dialysis to purify the blood of its waste products or a kidney transplant.

Proper diagnosis and treatment in the early stages of kidney disease can save the remaining function of the kidneys for many years.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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