Concussion is a type of brain injury. It is a complex injury that is challenging to evaluate and manage. The Concussion in Sport Group (CISG) international Consensus Statement defines concussion as ‘a traumatic brain injury, induced by biomechanical forces’. It generally results from a knock to the head, face or neck - but may be anywhere on the body which transmits force to the head. Concussion involves short-lived impairment of neurological function. Concussion is an evolving injury that may change over the first few hours or over a few days. In most adult cases, symptoms are resolved within 14 days of injury.