Most people don’t think about the function of their kidneys daily, but these essential organs are very important. The main job of the kidneys is to regulate the transport of water, salt, blood and nutrients in the body, while removing waste—through urine—that is no longer needed. Each day, these two bean-shaped, fist-sized organs filter about 130 quarts of blood and produce roughly 1.5 quarts of urine.
How the Kidneys Work
Each one of your kidneys contains an average of 1 million nephrons. Nephrons are the primary functional units of the kidney that regulate the amount of salt, water and nutrients that the body needs to keep or excrete via urine. The filtering system of the nephron, called the glomerulus, keeps blood cells and large proteins in circulation and filters fluid, electrically charged particles (ions) and smaller proteins into the tube-shaped structure of the nephron called the tubule. In the tubule, water, sugar, and salt can be reabsorbed to stay in your body, while waste is excreted. Specialized cells in the nephron can sense the levels of salt and water in the tubule and send signals to the blood vessels to control how quickly these materials are filtered. This process allows the kidneys to control the levels of salt and water in your body to maintain a healthy blood pressure.
While the kidneys may not be the most glamorous organs, they are vitally important to maintaining homeostasis in the body. Conditions such as high blood pressure, diabetes and heart disease can increase your risk for developing chronic kidney disease. When kidneys are severely damaged and can’t perform their cleansing function, patients may need dialysis, a treatment that removes waste and excess water from the blood using a special machine.
Keep your kidneys healthy and functioning well by eating a healthy diet, exercising, limiting alcohol and avoiding tobacco products. Work with your doctor to manage high blood pressure or diabetes. Your kidneys are taking care of you—so remember to take care of them.
Megan Rhoads, PhD, is a physiologist and postdoctoral fellow at the University of Alabama at Birmingham.