Transfusion medicine is the branch of medicine that encompasses all aspects of the transfusion of blood and blood components including aspects related to hemovigilance. It includes issues of blood donation, immunohematology and another laboratory testing for transfusion-transmitted diseases, management and monitoring of clinical transfusion practices, patient blood management, therapeutic apheresis, stem cell collections, cellular therapy, and coagulation. Transfusion Medicine specialists provide expert opinion on massive transfusions, difficult/incompatible transfusions and rational use of specialized blood product therapy like irradiated blood/washed blood products.