Blood transfusion is a process principally used to treat various medical conditions. This book deals with the applications of blood transfusion in diverse clinical surroundings. It discusses significant issues like the fundamental theories regarding ABO blood group system in blood transfusion, the use of transfusion in a variety of clinical surroundings, among others. It also deals with transfusion transmitted diseases, different techniques for allotransplantation and immunomodulatory effects of blood transfusion. The book covers various aspects of blood transfusion and will provide valuable information to its readers.