Hematoma: a mass of blood, usually clotted blood, resulting from a broken blood vessel, that forms in a tissue, organ.
For more terms, see our Migraine and Headache Glossary.
Medical review by John Claude Krusz, PhD, MD.
Teri Robert is a leading patient educator and advocate and the author of Living Well with Migraine Disease and Headaches. A co-founder of the Alliance for Headache Disorders Advocacy and the American Headache and Migraine Association, she received the National Headache Foundation's Patient Partners Award and a Distinguished Service Award from the American Headache Society.