Hematology is the branch of medicine that studies blood and diseases of the blood. It’s a word you’d hear at the hospital or doctor’s office, or if you’re having blood work done.
Add an -ology to the end of a word and it means “the study of.” Medical fields such as neurology and cardiology relate to the brain and the heart, respectively. Then there’s hematology, which involves something that goes to the heart, brain, and everywhere else in the body: blood. Hematology involves diseases of the blood such as leukemia. The Greek root for blood (haima) also appears in blood-related words such as hemorrhage and hematoma.