Asphyxia is a condition of severely deficient supply of oxygen to the body. In the absence of remedial action it will very rapidly lead to unconsciousness and death. Asphyxia is the same as suffocation and anoxia.

Asphyxia in humans is a medical emergency.

Causes of asphyxia can include:

• Crushing or constriction of the chest or abdomen
• Choking
• Drowning
• Strangulation, or external constriction of the neck or throat, e.g. by a rope (as in hanging), hands, or a snake
• Reduction of the airways due to anaphylaxis or asthma
• Inhalation of vomit
• Positional asphyxia
• Contact with a pulmonary agent or cyanogenic compound
• The extremely dangerous and frequently lethal practice of erotic asphyxiation, also called "breath control play"; including autoerotic asphyxiation
• A seizure which stops breathing activity
• Sleep apnea
• Low oxygen environments: eg. the filling of cryogenic vessels with liquified gases such as Nitrogen in an enclosed space. Another example is of workers climbing down into a fermentation vat in a brewery, not realising the vessle has filled with carbon dioxide.

Problems during childbirth can lead to the newborn experiencing asphyxia.

Prolonged asphyxia can result in brain damage even when it does not cause death.

See also

• hypoxia (medical)
• oxygen depletion (aquatic ecology)