hemodialysis

A procedure that cleans the blood and removes waste and excess water from the body of patients who have chronic kidney failure. During hemodialysis, the patient's blood is circulated through a machine, which contains a dialyzer -- often called an artificial kidney. The dialyzer has two chambers separated by a thin membrane. Excess water and waste pass from the blood through the membrane into the dialysis fluid, which is discarded. The cleaned blood is then returned to the patient's bloodstream.