This document discusses the Glasgow Coma Scale (GCS), which is used to assess head injuries. It provides background on head injuries and their causes before explaining the components of the GCS. The GCS assesses eye opening, verbal response, and motor response on a scale of 1-6 to determine a patient's level of consciousness following a head injury. Scores are categorized as mild, moderate, or severe injury. Though widely used to predict outcomes, the GCS does not account for all factors like focal signs or intoxication.