A head injury is any sort of injury to your brain, skull, or scalp. This can range from a mild bump or bruise to a traumatic brain injury. Concussions, skull fractures, and scalp wounds are all common head injuries. Depending on what caused your head injury and how severe it is, the implications and treatments differ dramatically.
There are two types of head injuries: closed and open. Any head injury that does not break your skull is referred to as a closed head injury. An open (penetrating) head injury occurs when anything penetrates your scalp and skull, allowing something to enter your brain.