Concussion; Brain injury - concussion; Traumatic brain injury - concussion; Closed head injury - concussion

A traumatic brain injury (TBI) can occur when the head hits an object, or a moving object strikes the head. There are three types of TBI:

  • Mild TBI, also called a concussion
  • Moderate TBI
  • Severe TBI

A TBI can affect how the brain works. The degree of impaired brain function and other symptoms and how long they will last depends on how severe the TBI is. A TBI may lead to headaches, changes in alertness, loss of consciousness, memory loss, and changes in thinking. Moderate to severe TBIs can cause life-long health problems.


The major areas of the brain have one or more specific functions.


A concussion may result when the head strikes against an object or is struck by an object. Concussions may produce unconsciousness or bleeding in or around the brain.



Exams and Tests


Outlook (Prognosis)

When to Contact a Medical Professional