Hematology (from ancient Greek. Αἷμα, αἷματος - blood + λόγος) is a branch of medicine that studies blood, hematopoietic organs and blood diseases. Hematology studies the etiology, diagnosis, treatment, prognosis and prevention of diseases of the blood system that affect the production of blood and its components, namely blood cells, hemoglobin, blood proteins, and the mechanism of coagulation (blood clotting). Scientific research in this area is often carried out by biomedical specialists. Hematologists are also engaged in research in the field of oncology - cancer treatment. Hematologists are physicians who specialize in the field of hematology. Their main task is to treat patients with hematological diseases, work in hematological laboratories with blood and bone marrow samples, and interpret the results of various hematological tests. In some institutions, hematologists also run hematology laboratories. In practice, at the main poles of the diff. Diagnostic hematology is often associated with a surgical discipline rather than a therapeutic one.