A head injury is any trauma to the scalp, skull, or brain. The injury may be only a minor bump on the skull or a serious brain injury and it can be open (penetrating) or closed type. Causes of head injury include accidents at home, work, outdoors, or while playing sports, falls physical assault, traffic accidents. Symptoms of head injury include bleeding, bruising, headache, feeling sick or nauseated, dizziness, passing out. Head injury is treated by neurologists and Neurosurgeons.