How Your Kidneys Work
The kidneys’ main job is to clean the blood. They filter wastes and excess fluids from thousands of pints of blood each day. In this way, they maintain the chemical balance the body needs to stay healthy and alive. One working kidney is enough to do this job. If both kidneys fail, their work must then be done another way.
Kidneys Filter the Blood
Your kidneys are located just above your waist toward your back. They filter blood by doing the following:
Removing waste and fluid. The kidneys take waste products from the blood. They also remove unneeded fluid.
Balancing chemicals. The body needs chemicals (such as calcium and phosphorus) to work. Too little or too much of them can make you sick. In the kidneys, chemicals are taken from or added to the blood to keep them in the right balance.
The Kidneys’ Other Tasks
In addition to filtering the blood, the kidneys do other tasks. These include:
Telling the body to make red blood cells (erythrocytes). These are the cells in the blood that carry oxygen.
Helping control blood pressure.
Helping keep bones strong.