A field of medicine that is a hybrid of laboratory and clinical practices. Transfusion medicine physicians are pathologists, hematologists, anesthesiologists, and pediatricians that are experts in the science and practice of blood transfusion. They practice in blood centers, hospitals, and clinics, and may interact with patients directly or only vicariously. The term is often used interchangeably with “blood banking,” but the two terms really refer to different things. The American Board of Pathology offers a certification in Blood Banking/Transfusion Medicine that requires specific training and demonstration of competence by examination.