Graceful Health: What do your kidneys do?
First question first: your kidneys are two bean-shaped organs, each about the size of your fist, located just below your rib cage and toward your back, near the spine. They are part of an important blood filtering system that extracts wastes and extra water, sending this out of your body through the bladder.
The kidneys are busy organs. They filter about 150-200 quarts of liquid each day. One or two of these are excreted as urine, and the rest of the liquid returns to the bloodstream.
How does this filtering happen? Inside each kidney, there are a million little filtering units called nephrons. The nephrons take in blood, send it through filters, and then pass it through tubes shaped like tiny twisted strands of spaghetti. This elaborate filtering process allows good nutrients to be absorbed back into the blood, and flushes out wastes and extra fluid as urine.
The second question — why do we have two kidneys — is hard to answer. We really don't know why, that's just the way it is. It's a good thing, though, because as vitally important as the kidneys are, it's good to have a backup system. The kidneys are necessary to proper functioning of the body. If one kidney fails, most people can lead normal lives with just one kidney, as long as they take good care of it.
Some people choose to live with one kidney. Kidney donation is fairly common. Sometimes, when a person faces death or great debilitation because of kidney failure, a family member or friend may donate a kidney. Other people are born with only one kidney, or a kidney that is not fully formed. They too can lead normal lives, as long as they protect the remaining kidney.
Kidneys perform other functions besides removing wastes and extra fluid. They also help to regulate salt, minerals, acids, and hormones in the body. For example, one hormone created in the kidneys stimulates the production of red blood cells; others regulate blood pressure and the absorption of calcium.
Kidneys are susceptible to damage from various diseases. These include polycystic kidney disease, an inherited tendency for cysts to form in the kidneys. Kidneys can also be damaged by congenital diseases, when something goes wrong for a baby developing in the womb.
Some kidney diseases are preventable. For example, diabetes and high blood pressure are leading causes of chronic kidney disease. So is the overuse of pain relievers, including aspirin, ibuprofen, naproxen sodium, and others. Kidney stones are another common kidney problem.
If you look at a list of common symptoms for chronic kidney disease, you will see that many of them could be attributed to other factors. The best diagnostic tool for determining whether your kidney is functioning properly is a regular blood test. Consult with your provider to get this test ordered and to discuss the test results, as certain factors such as age, gender, etc. can affect what is considered normal.
Most of the time, when the kidneys are doing their job properly, it's easy to forget they are there. Don't wait until you have a problem to have them tested. March is National Kidney Month, so it's a good time for a kidney check-up.
Dr. Maurice Geurts is a graduate of the University of Amsterdam Medical School. He completed his residency at the University of Vermont and joined the Grace Cottage staff in 2003.
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