Kidney disease affects an estimated 37 million people living in the United States, and, according to the National Kidney Foundation, it is “the under-represented public health crisis” — in part because around 90% of people who have chronic kidney disease aren’t aware that they have it or that it can lead to complete kidney failure. This lack of awareness about kidney disease highlights exactly why it’s so important to learn more about what it is, how to recognize it and the role it plays in kidney failure.
Your Kidneys: What They Do and How They Work
Like all your organs, your kidneys play an integral role in the overall healthy functioning of your body. These are two bean-shaped organs that sit just below your ribcage, with one on either side of your spine. Each kidney is about the size of your fist, but despite their relatively small size, they have a big job to do.
These organs are responsible for filtering your blood by removing excess water and waste products like old red blood cells and acids that other cells create. In order for your muscles, nerves and other tissues to function properly, your body needs to have a healthy balance of water and minerals like potassium, calcium and sodium. Your kidneys help maintain this balance as they filter out excess material your body doesn’t need (and that may disrupt that balance).
One lesser-known role your kidneys play is that they also produce and excrete several hormones. These stimulate your body to create new red blood cells in your bone marrow when your oxygen levels are lower, and they also help your body effectively absorb calcium and phosphate — substances that your nerves and muscles need in order to work properly together.
Each one of your kidneys has about a million nephrons, which are the tiny filtration units that process and clean your blood, and each nephron has two important structures called a glomerulus and a tubule. When your heart pumps blood into your renal arteries, which are the large blood vessels that lead to your kidneys, it travels through progressively smaller blood vessels until it reaches the nephrons’ glomeruli. The glomeruli catch and remove the waste products from your blood before passing it into the tubules, which circulate the filtered blood back into your body. Excess water and the filtered blood waste products move into structures called ureters, and you then excrete them as urine. All in all, your kidneys process and filter about 30 gallons of blood each day.