What causes and what are symptoms of transfusion reactions?

Fever, rapid pulse..: Transfusion reactions usually occur within minutes of the start of a transfusion or shortly after. Common symptoms are fever, sweating, rapid heart rate and shortness of breath. Other symptoms can include back or flank pain, bloody urine, fainting or dizziness. Transfusion reactions can range from very mild to life-threatening.

Immunologic or not: Causes for transfusion reactions may be immune related or not, also they can be acute (less than 24 hours) or delayed. These are some: hemolytic; febrile, non-hemolytic; bacterial contamination (septic shock); anaphylaxis; transfusion-related acute lung injury (trali); transfusion-associated circulatory overload (taco); graft vs. Host disease (ta-gvhd); iron overload; infections.