When a blow to the head shakes the brain within the space between the brain and the skull, the resulting shaking is known as concussion.A concussion is the most common type of head injury. A concussion can result from a car crash, a sports injury, a fall, or a violent shake to the head or upper body.

While most concussions are a temporary disturbance that don't leave lasting damage, it can lead to associated serious problems if not treated promptly and effectively.