A wound produced by the tearing of body tissue, as distinguished from a cut or incision. External lacerations may be small or large and may be caused in many ways, such as a blow from a blunt instrument, a fall against a rough surface, or an accident with machinery. Lacerations within the body occur when an organ is compressed or moved out of place by an external or internal force. This may result from a blow that does not penetrate the skin, and surgical repair is usually necessary.