DefinitionA hemolytic transfusion reaction is a serious problem that occurs after a patient receives a transfusion of blood. The red blood cells that were given to the patient are destroyed by the patient's own immune system.Alternative NamesBlood transfusion reactionCauses, incidence, and risk factorsBlood is classified into different blood types called A, B, AB, and O.The immune system normally can tell its own blood cells from blood cells from another person. If other blood cells enter your body, your immune system may make antibodies again them. These antibodies will work to destroy the blood cells that the body does not recognize. For example, a person with type A blood makes antibodies against type B blood cells.Another way blood cells may be classified is by Rh factors. People who h