A concussion is a type of traumatic brain injury—or TBI—caused by a bump, blow, or jolt to the head or by a hit to the body that causes the head and brain to move rapidly back and forth. This sudden movement can cause the brain to bounce around, twist, or shake in the skull, creating chemical changes in the brain and sometimes stretching and damaging brain cells.
You do not have to pass out or lose consciouness to have a concussion. Some people will have obvious outward symptoms of a concussion such as:
Appearing dazed or stunned
Confusion
Forgetfulness
Clumsy movement