Hematoma vs. Ecchymosis

Hematoma

A hematoma (US spelling) or haematoma (UK spelling) is a localized collection of blood outside the blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is initially in liquid form spread among the tissues including in sacs between tissues where it may coagulate and solidify before blood is reabsorbed into blood vessels. An ecchymosis is a hematoma of the skin larger than 10mm.

They may occur among/within many areas such as skin and other organs, connective tissues, bone, joints and muscle.

A collection of blood (or even a hemorrhage) may be aggravated by anticoagulant medication (blood thinner). Blood seepage and collection of blood may occur if heparin is given via an intramuscular route; to avoid this, heparin must be given intravenously or subcutaneously.

It is not to be confused with hemangioma, which is an abnormal buildup/growth of blood vessels in the skin or internal organs.

Ecchymosis

An ecchymosis is a subcutaneous spot of bleeding (from extravasation of blood) with diameter larger than 1 centimetre (0.39 in). It is similar to (and sometimes indistinguishable from) a hematoma, commonly called a bruise, though the terms are not interchangeable in careful usage. Specifically, bruises are caused by trauma whereas ecchymoses, which are the same as the spots of purpura except larger, are not necessarily caused by trauma, often being caused by pathophysiologic cell function, and some diseases such as Marburg virus disease.

A broader definition of ecchymosis is the escape of blood into the tissues from ruptured blood vessels. The term also applies to the subcutaneous discoloration resulting from seepage of blood within the contused tissue.

Ecchymosis (noun)

a discoloration of the skin resulting from bleeding underneath, typically caused by bruising

“the infrequent association of bacterial sepsis with ecchymoses”

“there are signs of ecchymosis”