Kidneys keep the levels of electrolytes stable such as sodium, potassium and phosphate. They help regulate nerve and muscle function and maintain water balance. Electrolytes are minerals that carry an electric charge when they are dissolved in a liquid such as blood. If the electrolyte concentration is high, fluid moves into that compartment through osmosis. Whereas, if the electrolyte concentration is low, fluid moves out of that compartment. In order to balance, fluid levels, the body can actively move electrolytes in or out of cells. Therefore, regulating electrolytes and maintaining its balance If fluid levels or electrolyte levels are not balanced, many bodily functions will fail to proceed at their normal rates. For example, ADH, which is a peptide hormone secreted by the pituitary gland/hypothalamus (The hypothalamus is an osmoreceptor which reacts to changes in osmotic pressure and has an effect on the pituitary gland.) located near the brain, is responsible in reducing sodium concentration in the blood by increasing water re-absorption in the kidneys to dilute bodily fluids. In other words, they filter sodium and water from the blood and excrete any excess substance via urine. The kidneys can conserve water by producing urine that is concentrated relative to plasma, or they can rid the body of excess water by producing urine that is dilute relative to plasma.