Both surface hematomas and ecchymosis are signs of bleeding on and underneath the skin.
An ecchymosis is a purple or red discoloration of the skin due to leakage of red blood cells from small ruptured vessels (smaller versions are called petechia – 1-2 mm; purpura – 3 to 10 mm; and ecchymosis – more than 10 mm). It is flat. It is commonly referred to as a bruise.
A hematoma is a collection of blood clots in the tissue. It has substance in that it can be felt like a mass.
Note: hemorrhage is active bleeding whereas hematomas and ecchymoses are blood that have clotted or not actively bleeding.
Hematoma on the foot. Notice the swelling or bulge with bluish discoloration.
Hematoma after an operation showing the blood being aspirated.
Ecchymosis after a needle aspiration biopsy.
Ecchymosis or bruise after a breast trauma.
Petechiae and purpura (differ in size)