Drowning is death caused by the filling of the lungs by a liquid, usually water, rendering breathing ineffective and leading to death due to asphyxia. Near drowning is initial survival of a drowning event, and can lead to serious secondary complications including death later on; cases of near drowning therefore also require attention by medical professionals. Secondary drowning is death due to chemical and biological changes in the lungs after a near drowning incident or exposure to chemicals. In many countries, drowning is one of the leading causes of death for children under 14 years old.