WHAT IS A CONCUSSION? A concussion is a brain injury. Concussions are caused by a bump or blow to the head. Even a “ding,” “getting your bell rung, ” or what seems to be a mild bump or blow to the head can be serious.
You can’t see a concussion. Signs and symptoms of concussion can show up right after the injury or may not appear or be noticed until days or weeks after the injury.