Hematology (American English) or haematology (British English) is the branch of biology (physiology), pathology, clinical laboratory, internal meicine, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases. Hematology includes the study of etiology, diagnosis, treatment, prognosis, and prevention of blood diseases. The lab work that goes into the study of blood is performed by a Medical Technologist.