Hematology, also spelled haematology (from the Greek ‘αἷμα haima "blood" and -λoγία), is 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 that affect the production of blood and its components, such as blood cells, hemoglobin, blood proteins, and the mechanism of coagulation. The laboratory work that goes into the study of blood is frequently performed by a medical technologist. Hematologists also conduct studies in oncology—the medical treatment of cancer.
Physicians specialized in hematology are known as hematologists or haematologists. Their routine work mainly includes the care and treatment of patients with hematological diseases, although some may also work at the hematology laboratory viewing blood films and bone marrow slides under the microscope, interpreting various hematological test results and blood clotting test results. In some institutions, hematologists also manage the hematology laboratory. Physicians who work in hematology laboratories, and most commonly manage them, are pathologists specialized in the diagnosis of hematological diseases, referred to as hematopathologists. Hematologists and hematopathologists generally work in conjunction to formulate a diagnosis and deliver the most appropriate therapy if needed. Hematology is a distinct subspecialty of internal medicine, separate from but overlapping with the subspecialty of medical oncology. Hematologists may specialize further or have special interests, for example, in:
Hematology as basic medical science
(abnormality of the hemoglobin molecule or of the rate of hemoglobin synthesis)