“Keeping Us in Balance: The Work of the Kidneys”

Prairie Doc perspective Week of December 28th, 2025
“Keeping Us in Balance: The Work of the Kidneys”
By Andrew Ellsworth, MD


Picture a man crawling through the desert in tattered clothing, whispering “water” as he nears an oasis. He isn’t thinking about his kidneys, yet they may be the main organ still keeping him alive.


The human body does an amazing job at maintaining the balance of our internal environment, known as homeostasis. The kidneys, those two bean-shaped organs at our sides, are vital for maintaining that balance. Through filtration, reabsorption, and the secretion of hormones, the kidneys are one (or two) of our most important organs. 


Each day, the kidneys filter roughly 50 gallons of blood, enough to fill a bathtub. In doing so, they remove waste products and toxins that would otherwise build up and cause harm. They also regulate electrolytes such as sodium, potassium, calcium, and phosphate, which are essential for proper muscle, nerve, and heart function.


The kidneys regulate our fluid balance. If we are dehydrated, they will reabsorb more fluid back into the bloodstream.  Meanwhile, if there is excess, they will increase urine production.  On a normal day, a healthy person usually only needs to drink when feeling thirsty.  Anti-diuretic hormone is secreted by the brain when you start to get dehydrated, telling the kidneys to retain more fluid, and giving yourself the sensation of thirst.


The kidneys help regulate blood pressure through their control of salt and water retention or excretion. They maintain acid-base balance, keeping the body’s pH within a narrow, safe range. In addition, the kidneys secrete hormones involved in bone health and stimulate the bone marrow to produce red blood cells.


With all these responsibilities, preserving kidney health is essential. You can support your kidneys by preventing imbalance where possible. Eat a healthy diet low in salt and added sugar. See your healthcare provider regularly to screen for diabetes and monitor blood pressure, the two leading causes of chronic kidney disease. Avoid taking excessive amounts of medications such as ibuprofen or naproxen. Other prescription and over-the-counter drugs, supplements, and herbal preparations can strain the kidneys as well—so use them carefully and follow directions.


With the kidneys, balance is key. Avoid excess, protect your health, and your kidneys will likely manage the rest. Whether you are sleeping soundly at home or desperately seeking water under a desert sun, your kidneys continue their quiet work—filtering, regulating, protecting, and keeping your body in balance.


Dr. Andrew Ellsworth is a Family Medicine Physician at Avera Medical Group Brookings in Brookings, SD. He serves as one of the Prairie Doc Volunteer Hosts during its 24th Season providing Health Education Based on Science, Built on Trust. Follow The Prairie Doc® at www.prairiedoc.org, Facebook, Instagram, YouTube, and Tik Tok. Prairie Doc Programming includes On Call with the Prairie Doc®, a medical Q&A show (most Thursdays at 7pm on SDPB, YouTube and streaming on Facebook), 2 podcasts, and a Radio program (on SDPB, Sundays at 6am and 1pm).