Kidney Health

How Kidneys Work

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine. Every day, the two kidneys filter about 120 to 150 quarts of blood to produce about 1 to 2 quarts of urine, composed of wastes and extra fluid. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of the bladder. The bladder stores urine. The muscles of the bladder wall remain relaxed while the bladder fills with urine. As the bladder fills to capacity, signals sent to the brain tell a person to find a toilet soon. When the bladder empties, urine flows out of the body through a tube called the urethra, located at the bottom of the bladder.

The kidneys are important because they keep the composition, or makeup, of the blood stable, which lets the body function. They prevent the buildup of wastes and extra fluid in the body and keep levels of electrolytes stable, such as sodium, potassium, and phosphate. The kidneys make hormones that help regulate blood pressure, make red blood cells, and keep bones strong.


Food and beverages provide the energy and nutrients needed to improve health, manage disease, and reduce the risk of disease. Depending on your loved one’s condition, they may need to limit specific ingredients and the amount of liquids consumed.

Here are some resources from the National Kidney Disease Education Program and the National Institute of Diabetes and Digestive and Kidney Diseases to help you understand what, when, how often, why, and how much to eat and drink, as well as, help manage kidney disease and prevent kidney stones.


Physical activity is an important part of staying healthy. Being active makes the muscles, bones, and heart stronger. Physical activity also makes your blood circulate faster so the body gets more oxygen. The body needs oxygen to use the energy from food. If your loved one is on dialysis, physical activity can help more wastes move into their blood for dialysis to remove them. Exercise can also help manage diabetes and high blood pressure, which are common causes of kidney disease. Physical activity can also improve mood and provide a sense of well-being. Talk with the doctor before starting an exercise routine. Start slow, with easier activities such as walking at a normal pace or gardening. Work up to harder activities such as walking briskly or swimming. Aim for at least 30 minutes of exercise most days of the week.