A<unk> , or<unk> , is a collection of blood, generally the result of hemorrhage, or, more specifically, internal bleeding.<unk> s exist as bruises (ecchymoses), but can also develop in organs.<unk> s can also be under the nails, causing a brown-black discoloration. Some<unk> s form into a welt- like formation that is hard to the touch, which is a sac of blood that the body creates to keep internal bleeding to a minimum. In most cases the sac of blood eventually dissolves, however in some cases they may continue to grow or show no change. If the sac of blood does not disappear it may need to be surgically removed.
It is not to be confused with hemangioma which is an abnormal build up of blood vessels in the skin or internal organs.<unk> s can gradually migrate, as the effused cells and pigment move in the connective tissue. For example, a patient who injures the base of his thumb might cause a<unk>  which will slowly move all through the finger within a week. Gravity is the main determinant of this process.<unk> s on articulations can reduce mobility of a member and present roughly the same symptoms as a  fracture.
Hematoma
Angioma
Coma
Noma
Lymphangioma
Blood cyst
Aneurysm
Hemangioma