Dialysis is a mechanical process that performs the work that healthy kidneys would do. It clears wastes and extra fluid from the body and restores the proper balance of chemicals (electrolytes) in the blood. When chronic kidney disease becomes so severe that your kidneys are no longer working properly, you may need dialysis. You may use dialysis to replace the work of the kidneys for many years. Or dialysis may be a short-term measure while you are waiting for a kidney transplant.
Hemodialysis uses a man-made membrane called a dialyzer to clean your blood. You are connected to the dialyzer by tubes attached to your blood vessels. Before hemodialysis treatments can begin, a surgeon creates a site where blood can flow in and out of your body. This is called the dialysis access. Usually the doctor creates the access by joining an artery and a vein in the forearm or by using a small tube to connect an artery and a vein. An access may be created on a short-term basis by putting a small tube into a vein in your neck, upper chest, or groin.
Peritoneal dialysis uses the lining of your belly, which is called the peritoneal membrane, to filter your blood. Before you can begin peritoneal dialysis, a surgeon needs to place a catheter in your belly to create the dialysis access.