Hematology - The Study of the Blood

Hematology is a scientific and medical discipline that involves the study of the blood and blood-forming tissues. Hematologists in clinical practice are trained to diagnose and treat diseases of the blood such as hemophilia, sickle cell anemia, and clotting disorders as well as cancers of the blood, such as leukemia. Hematologists can perform bone marrow aspirations and biopsy but also prepare the biopsy for analysis in the laboratory and make a diagnosis based on the sample. Hematologists are also skilled at analyzing peripheral blood smears, that is, blood that has been smeared on a microscope slide so that a thin layer of blood and blood cells can be seen. This type of analysis is important for the diagnosis of blood parasites, like malaria, for example. A hematologist is usually called upon to oversee the blood bank inside of hospitals and larger clinics. Because an incorrect transfusion and subsequent reaction can rapidly lead to death, hematologists tightly regulate who receives blood transfusions and blood products. Hematology covers the baffling disorders of blood clotting as well—these doctors make sense of a complex cascade of enzymes that can be lethal when they go awry.

 

 

In medicine, the field of hematology overlaps with the field of oncology, which is concerned with the diagnosis and treatment of cancer. In many hospitals, hematology and oncology are usually housed within the same department (Hematology Oncology or simply Heme/Onc). This combination makes good sense since those trained in hematology have experience in the diagnosis and treatment of leukemia, lymphoma, polycythemia vera, and other blood and blood-forming tissue malignancies.

 

To become certified in hematology in the United States, a physician with an MD or DO degree must first complete residency training in internal medicine and then fellowship training in hematology. In some other countries, hematology is its own separate residency. Since much of the diagnosis in hematology is based on laboratory hematology tests, about half of U.S. hematology residency training is based in a laboratory while the other half involves direct patient care. Often a hematology fellowship is two years; that means that after college, a hematologist spends four years in medical school, three years in internal medicine residency and two years in hematology fellowship.

 

From a scientific and biomedical research perspective, hematology is at the forefront of cutting edge techniques, such a cancer chemotherapy and stem cell research. Hematology also overlaps with the field of immunology, since white blood cells are an important part of the immune system. Clinical or graduate training in hematology prepares scientists for an excellent foundation for performing research on various autoimmune and degenerative diseases. In fact, stem cell research, that is, the precursor cells from which all other cell types are created, has potential applications in almost every disease known to man. Stem cells could be used to treat everything from Parkinson’s disease to diabetes. Hematology as a field, in both clinical and research capacities promises to yield some of the most valuable therapies of the 21^st century.