Molecular Any injury sustained from blunt force, which may be related to MVAs, or mishaps, falls or jumps, blows or crush injuries from animals, blunt objects or unarmed assailants. Cf Penetrating trauma. A wound in which the surface of the skin remains intact, caused by impact or collision with a blunt object, e.g., an automobile fender.
Mastoiditis occurs when ear infections cause infection in the mastoid bone. The mastoid bone can be found directly behind the ear. Mastoiditis causes the area behind the ear to swell and protrude out of the skin. The bump behind ear is accompanied with fever, ear pain, hearing loss and ear redness.
One painless lump behind ear type is called lipoma. This is a relatively harmless deposit of fat under the skin. It can also be found on the neck, back, shoulders, arms and thighs, but normally it is a soft painless lump behind the ear that is due to the development of fatty tissue that grows slowly under the skin.