A head injury is a broad term that describes a vast array of injuries that occur to the scalp, skull, brain and underlying tissue and blood vessels in the head. They are indiscriminate and range from minor bumps to catastrophic injury. Many go undetected for some time. They affect all age ranges and can range from a fall off a bike to a subarachnoid haemorrhage. Many of those affected suffer no long-lasting visible physical disability and so it is an invisible and often silent injury.
It can lead to isolation, unemployment, and family, and friends believinge there is a "personality change" which puts a strain on relationships.
They can occur with no notice and the impact as can be seen is dramatic.