In clinical medicine, the term dialysis refers to a procedure that replaces the function of the kidneys when they no longer work adequately. It is therefore also referred to as a renal replacement therapy procedure. Dialysis is used to remove excess water and waste as well as excretory products from the blood, which would otherwise lead to life-threatening symptoms of poisoning. Colloquially, the term dialysis is usually understood to mean hemodialysis or blood washing, although other procedures (e.g. peritoneal dialysis) can also be performed.
Patients with severe chronic kidney disease need permanent kidney replacement therapy because the body produces new excretory products. Dialysis accompanies those affected for the rest of their lives or until the diseased kidneys are replaced by a kidney transplant.