Removal of unwanted or pathological components from a patient's blood by means of a continuous-flow separator: "The therapeutic apheresis is similar to the process of hemodialysis, because detoxified blood is returned to the patient."

"The removal of cellular material is termed cytapheresis; leukapheresis describes the removal of leukocytes only. Plasmapheresis, also called plasma exchange, involves removal of noncellular materials."

Therapeutic aspharesis has been used to treat blood hyperviscosity, cold agglutinin hemolytic anemia, posttransfusion purpura, thkrombotic thrombocytopenic purpura, myasthenia gravis, sickle cell anemia, Guillain-Barre syndrome, familial hypercholesterolemia, and even certain drug overdoses."