A closed head injury refers to any type of head injury that does not involve skull fracture. Such injuries can range from mild concussions to more severe traumatic brain injuries. There are several synonyms commonly used to describe closed head injuries, including brain injury, head trauma, head injury, and concussion. These terms are often used interchangeably depending on the severity and specific nature of the injury. Symptoms of closed head injuries may include headache, dizziness, confusion, memory loss, and difficulty concentrating. It is important to seek medical attention immediately following any head injury to ensure proper diagnosis and treatment.