Asphyxia or asphyxiation is a condition when a living body does not get enough oxygen. If this condition lasts long enough it can lead to unconsciousness, brain damage and death.

Asphyxia can injure or kill people. This sometimes happens during suicide, torture, and in warfare. It can also be used as a capital punishment. It is also sometimes used (non fatally in martial arts, and combat sports)Because the need to breathe is controlled by the amount of carbon dioxide in the lungs with blood, some victims may not experience an urgent need to breathe and may remain unaware of the shortage of oxygen in their body.