A procedure in which the blood is filtered, separated, and a portion retained, with the remainder being returned to the individual patient.

There are various types of pheresis.

• In leukapheresis, the leukocytes (white blood cells) are removed.
• In plateletpheresis, the thrombocytes (blood platelets) are removed.
• In plasmapheresis, the liquid part of the blood (the plasma) is removed.