Minor head injury, also often referred to as concussion, mild head injury or minor brain injury, may be defined as a trauma-induced alteration in mental status (confusion) that may or may not involve loss of consciousness. Most minor head injuries result in no long-term damage to the brain. However it can cause temporary disruption of brain function. People who have had a minor head injury often experience Post-traumatic amnesia (PTA) of less than one hour after the injury. This is a period where they act strangely and confuse and are unable to remember what has just happened.
Minor head injury is commonly caused by falls, road crashes, assaults and sports accidents.