Renal dialysis, or kidney dialysis, is the physical filtering procedure used to artificially remove waste products and excess water from the blood stream. The kidneys are the filtering organs that generally perform this task for us. They control the salt, electrolyte and fluid balance in the bloodstream necessary for all the systems in the body to function properly. If the kidneys become damaged or diseased and their filtering ability compromised, toxins and water accumulate in the bloodstream and will eventually poison the person if nothing is done to help them. Renal dialysis is used as a bridging procedure until either the kidney functions are restored, or the patient gets a kidney transplant. In the case of renal disease, the kidney's filtering mechanism becomes damaged, inefficient and inaccurate. Some molecules such as blood cells and some proteins are passed into the urine and excreted, while dangerous salts and water are often retained. Renal dialysis does not work as efficiently as a healthy kidney, but it does remove the most dangerous salts and the excess water accumulated in the body. Dialysis does not cure kidney disease, it merely performs the most basic functions of the kidney necessary for the body to continue living normally. Dialysis has to be repeated at frequent intervals. There are two basic types of renal dialysis, hemodialysis and peritoneal dialysis. The principle behind the dialysis is that salts and water can pass through a semi-permeable membrane from one container to another. When the specific salt solutions are mixed in the correct concentration, they can "draw" other salts and water to themselves. The dialysis fluid used is scientifically formulated to do just this. In hemodialysis, blood from the patient is taken via a tube in their arm, into a machine. In the machine, the blood flows on one side of the membrane and the dialysis fluid is pumped on the opposite side and in the opposite direction. The blood is thus cleansed and flows back into the patient. The process takes up to 3 to 5 hours and is necessary at least 2 to 3 times a week. Most people needing hemodialysis have to attend a day center where it is performed. The whole procedure is very disruptive to the lifestyle of dialysis patients. Peritoneal dialysis is usually performed at home. It is far less disruptive to lifestyle, but needs to be performed at least daily or preferably twice a day. A special connection is inserted into the patient's peritoneum (abdominal cavity). The patient himself then attaches the dialysis mixture and allows it to flow in. The peritoneum or mucus lining of the abdominal cavity is full of blood vessels, it acts as the membrane between the blood vessels and the dialysis fluid. The fluid is left in the peritoneum for a few hours, allowing it to do its work, then it is drained out and discarded. Peritoneal dialysis is not as efficient as hemodialysis, but, because it is done more frequently, the results are on a par. Renal dialysis is a life-saving procedure to filter toxins and excess fluids out of the bloodstreams of patients suffering from damaged and diseased kidneys. Dialysis helps restore the electrolyte and water balances the body requires to function efficiently, so patients with severe renal damage can continue to live relatively normal lives when their kidneys fail.   Article Source: