A serious injury is an injury from a road crash with enough severity to require hospitalisation. This excludes injuries from road crashes as a result of natural causes, such as a heart attack.
A severe injury is defined as a hospitalised injury case with an injury severity score greater than 12 (ISS>12) or death after injury resulting from non-intentional external causes. It is estimated that severe injuries account for around 8 per cent of all hospitalisations resulting from road crashes in Australia. In 2018-19, 39,755 people were seriously injured on Australian roads.