Is an abnormal collection of blood outside of a blood vessel. It occurs because the wall of a blood vessel wall, artery, vein, or capillary, has been damaged and blood has leaked into tissues where it does not belong.
Symptoms:
Blood that escapes from within a blood vessel is very irritating to the surrounding tissue and may cause symptoms of inflammation including pain, swelling, and redness. Symptoms of a hematoma depend upon their location, their size, and whether they cause associated swelling or edema.