Drowning is death from asphyxia due to suffocation caused by water entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia.

Near drowning is the survival of a drowning event involving unconsciousness or water inhalation and can lead to serious secondary complications, including death, after the event.

According to the World Health Organization, drowning is the 3rd leading cause of unintentional injury death worldwide, accounting for 7% of all injury related deaths (est. 388,000 deaths by drowning in 2004, excluding those due to natural disasters), with 96% of these deaths occurring in low- and middle-income countries. In many countries, drowning is one of the leading causes of death for children under 12 years old. For example, in the United States, it is the second leading cause of death (after motor vehicle crashes) in children 12 and younger. The rate of drowning in populations around the world varies widely according to their access to water, the climate and the national swimming culture.

Drowning itself is quick and silent, although it may be preceded by distress which is more visible. A person drowning is unable to shout or call for help, or seek attention, as they cannot obtain enough air. The instinctive drowning response is the final set of autonomic reactions in the 20 – 60 seconds before sinking underwater, and to the untrained eye can look similar to calm safe behavior. Lifeguards and other persons trained in rescue learn to recognize drowning people by watching for these instinctive movements.