Every unit of blood a nurse hangs represents a living tissue transplant, and the margin for error is narrow. This course provides a deep, practice-oriented examination of transfusion therapy from the ground up, beginning with the immunohematology of the ABO and Rh systems and the compatibility testing that keeps patients safe. Learners move through the full spectrum of blood components and their specific indications, the shift toward restrictive, evidence-based transfusion thresholds and patient blood management, and the step-by-step mechanics of safe administration. Substantial attention is devoted to recognizing and managing the full range of acute and delayed transfusion reactions, including the ones most often missed at the bedside such as transfusion-associated circulatory overload and transfusion-related acute lung injury. The course closes with focused guidance on high-stakes and specialized situations, including massive transfusion and hemorrhage control, autotransfusion, neonatal and pediatric transfusion, exchange transfusion, sickle cell disease, and the care of patients who decline blood products. Throughout, content is anchored in current AABB, CHEST, ASH, and patient blood management guidance and translated directly into the clinical decisions nurses make during a transfusion.