A traumatic brain injury (TBI) is caused by a blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain. The severity of a TBI may range from mild, such as a brief change in mental status or a temporary loss of consciousness to severe, such as an extended period of loss of consciousness or amnesia. In the United States, there are over 1.4 million traumatic brain injuries each year. Of those 1.4 million, over 200,000 require hospitalization for those injuries, and 50,000 of those TBIs result in death.
While most brain injuries are associated with some sort of trauma, in many cases the injury to the brain is caused by a lack of oxygen. Head traumas often cause swelling in the brain, and swelling causes decreased blood flow resulting in oxygen deprivation. When the brain is deprived of oxygen for an extended length of time, the brain will be damaged or die. It is this lack of oxygen that causes many injuries and deaths.