Hematoma: An abnormal localized collection of blood in which the blood is usually clotted or partially clotted and is usually situated within an organ or a soft tissue space, such as within a muscle.
A hematoma is caused by a break in the wall of a blood vessel. The break may be spontaneous, as in the case of an aneurysm, or caused by trauma.
The treatment of a hematoma depends on its location and size. Treatment can involve draining the accumulated blood. A hematoma in or near the brain is particularly dangerous.
The word "hematoma" came into usage around 1850. It was devised from Greek roots -- hemat-, referring to the blood + -oma, from soma meaning body = a bloody body, or a collection of blood.
The many different kinds of hematomas are defined by location and include: