Traumatic brain injury is also referred to as intracranial injury, or just by the short acronym TBI. It is typically the result of an external force injuring the brain. For example, a driver hitting the steering wheel in a car crash. TBI is usually classified based upon its severity, what kind of injury it is (closed or penetrating) and the location of the injury. Although most medical personnel refer to head injuries as TBI, it is really a much larger category, as it also refers to injuries to the skull and scalp. Head injury and brain injury are often used to mean the same thing.
TBI is devastating, and in most cases, permanent. People may sustain TBI as a result of violence, a slip and fall, sports related injuries, vehicle wrecks (car, truck, motorcycle) and explosive devices used in war zones. Trauma to the brain may be caused by either acceleration or a direct impact. Acceleration and impact injuries may create a situation called a contrecoup effect, where on impact (coup) one side of the brain is injured and on the rebound inside the head (contrecoup), the brain then slams into the other side of the skull. It is bruising of the brain.
The trauma itself is the primary injury, but it also results in secondary injuries that may include pressure in the skull and damage to the cerebral blood flow. Ultimately, this type of injury can result in changes in behavior, emotional issues, cognitive difficulties, physical impairment, permanent disability and/or death.
There are two categories of TBI, and the first one is referred to as acquired brain injury. The second is non-traumatic brain injury that does not involve external force. Non-traumatic brain injury would include events such as brain infections and strokes.