The function of the kidneys is to excrete urine, which contains the end products of metabolism, and to help regulate the wastes, electrolyte and acid content of the blood. To accomplish this, the kidneys conserve water and balance electrolytes by reabsorbing the exact amounts required minute by minute and sending the excess out through the urinary tract. This is done through a complex network of electrochemical responses, including the brain, nervous system, and endocrine (hormone producing glands).
The kidneys have the heavy responsibility of removing waste and toxins from the bloodstream. Kidneys adjust the body's acid/alkaline balance and regulate the number of fluids in your body. Kidneys also produce several essential hormones. A kidney cleanse is done in order to cleanse the delicate kidney tubules and supporting tissues from foreign substances which have collected there due to the body's inability to eliminate them via the usual way, namely the ureters, urinary bladder, and urethra (urinary apparatus).