Hypoxia is a pathological condition in which the body as a whole (generalized hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. Hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia.
Hypoxia is often associated with high altitudes, where it is called altitude sickness. Hypoxia can also occur while diving underwater, especially with closed-circuit rebreather systems that control the amount of oxygen in the air breathed in.
Symptoms of generalized hypoxia depend on its severity and speed of onset. They include headaches, fatigue, shortness of breath, nausea, unsteadiness, and sometimes even seizures and coma. Severe hypoxia induces a blue discoloration of the skin (deoxygenated blood cells lose their bright red color in favor of a dark blue/red color).
Categories of hypoxia
See also
