Hematology is that medical specialty which concerns itself with the blood, and the generation of blood in the bone marrow. Hematology studies the red and white blood cells, their relative proportions and general cell health, and the diseases that are caused by imbalances between them, notably leukemia and anemia. Red blood cells carry oxygen from the lungs to the various parts of the body, and white blood cells fight infections. Both are necessary, but they have to be in the body in the right proportions or systems will break down.
Oncology, at its most basic level, involves the diagnosis and treatment of cancer. The word oncology comes from the Greek word meaning "mass" or "bulk," referring to tumors. A doctor who specializes in oncology is called an oncologist.
Oncology involves a huge range of study. Since cancer can occur in so many of the body's systems, many doctors choose to specialize in a particular branch of it, such as bone cancer or blood diseases. Some doctors specialize in chemotherapy treatments, while others focus on radiation therapy. Most doctors who specialize in oncology serve internships and residencies that focus on cancer treatment, usually in their preferred branch of therapy. A specialist often serves about four years beyond the normal residency period.
Oncology also involves research into cancer, its causes and possible cures. This is also a wide-open field for scientists interested in a variety of research opportunities. Some facilities, such as St. Jude's Children's Hospital, in Memphis, Tennessee, is primarily a research institution. Oncology researchers continue to look for ways to treat even the rarest forms of cancer in humans.
