Head injury can be classified as either closed or penetrating. In closed head injury, the head sustains a blunt force by striking against an object. In penetrating head injuries, a high velocity object breaks through the skull and enters the brain. The signs and symptoms of a head injury may occur immediately or develop slowly over several hours.
Review Date 10/16/2017
Updated by: Jesse Borke, MD, FACEP, FAAEM, Attending Physician at FDR Medical Services/Millard Fillmore Suburban Hospital, Buffalo, NY. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.