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hematology

American  
[hee-muh-tol-uh-jee, hem-uh-] / ˌhi məˈtɒl ə dʒi, ˌhɛm ə- /

noun

Medicine/Medical.
  1. the study of the nature, function, and diseases of the blood and of blood-forming organs.


hematology Scientific  
/ hē′mə-tŏlə-jē /
  1. The branch of medicine that deals with the blood and blood-producing organs.


Other Word Forms

  • hematologic adjective
  • hematological adjective
  • hematologist noun

Etymology

Origin of hematology

First recorded in 1805–15; hemato- + -logy

Explanation

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.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Sanofi SAN -0.66%decrease; red down pointing triangle said two bleeding disorder treatments for both chronic and acute conditions have been approved in China, expanding its hematology offerings in the country.

From The Wall Street Journal • Dec. 11, 2025

The company’s strength lies in its diversification, with its portfolio of more than 30 products and an extensive pipeline across hematology, oncology, cardiology, immunology, and neuroscience.

From Barron's • Nov. 20, 2025

Ph.D., professor of hematology and oncology, J. Chad Brenner, Ph.D., associate professor of otolaryngology-head and neck surgery, and Paul L. Swiecicki, M.D., associate medical director for the Oncology Clinical Trials Support Unit at Rogel.

From Science Daily • Apr. 16, 2024

Floy Agnes Lee, known as Aggie, was a hematology technician at Los Alamos.

From Scientific American • Jul. 27, 2023

“You are a specialist in hematology employed by the Anacortes General Hospital— is that correct? Do I have that right?”

From "Snow Falling on Cedars: A Novel" by David Guterson