OverviewHead 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.
Update Date 1/13/2014
Updated by: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.