Healthy kidneys perform a variety of functions in the human body, all of which combine to promote overall health. According to the National Kidney Foundation, every 30 minutes the kidneys filter all the blood in a person’s body, removing any waste and excess fluid. Healthy kidneys also regulate the body’s fluid levels while releasing a hormone that regulates blood pressure. That’s an especially important function, as high blood pressure often has no symptoms but has been linked to a host of ailments, including heart attack and stroke. Healthy kidneys also release the hormone that directs production of red blood cells, which the University of Rochester Medical Center notes are responsible for carrying fresh oxygen throughout the body. Such functions become more difficult to perform if the kidneys are not operating at optimal capacity, which they cannot do when a person has kidney disease. Healthy kidneys also help to keep blood minerals in balance, and that balance can help a person maintain normal blood pressure.