Editing Hypoxia (medicine) (section)

===Prevention of altitude induced hypoxia===
To counter the effects of high-altitude diseases, the body must return arterial P<sub>a<sub>O<sub>2</sub></sub></sub> toward normal. [[Acclimatization]], the means by which the body adapts to higher altitudes, only partially restores P<sub>O<sub>2</sub></sub> to standard levels. [[Hyperventilation]], the body's most common response to high-altitude conditions, increases alveolar P<sub>O<sub>2</sub></sub> by raising the depth and rate of breathing. However, while P<sub>O<sub>2</sub></sub> does improve with hyperventilation, it does not return to normal. Studies of miners and astronomers working at 3000 meters and above show improved alveolar P<sub>O<sub>2</sub></sub> with full acclimatization, yet the P<sub>O<sub>2</sub></sub> level remains equal to or even below the threshold for continuous oxygen therapy for patients with [[chronic obstructive pulmonary disease]] (COPD).<ref name="West 2004 789–800" /> In addition, there are complications involved with acclimatization. [[Polycythemia]], in which the body increases the number of red blood cells in circulation, thickens the blood, raising the risk of blood clots.<ref name="NHS" />

In high-altitude situations, only oxygen enrichment or compartment pressurisation can counteract the effects of hypoxia. Pressurisation is practicable in vehicles, and for emergencies in ground installations. By increasing the concentration of oxygen in the at ambient pressure, the effects of lower barometric pressure are countered and the level of arterial P<sub>O<sub>2</sub></sub> is restored toward normal capacity. A small amount of supplemental oxygen reduces the equivalent altitude in climate-controlled rooms. At 4000&nbsp;m, raising the oxygen concentration level by 5% via an oxygen concentrator and an existing ventilation system provides an altitude equivalent of 3000&nbsp;m, which is much more tolerable for the increasing number of low-landers who work in high altitude.<ref name="West 1995" /> In a study of astronomers working in Chile at 5050&nbsp;m, oxygen concentrators increased the level of oxygen concentration by almost 30 percent (that is, from 21 percent to 27 percent). This resulted in increased worker productivity, less fatigue, and improved sleep.<ref name="West 2004 789–800"/>

[[Oxygen concentrator]]s are suited for high altitude oxygen enrichment of climate-controlled environments. They require little maintenance and electricity, utilise a locally available source of oxygen, and eliminate the expensive task of transporting oxygen cylinders to remote areas. Offices and housing often already have climate-controlled rooms, in which temperature and humidity are kept at a constant level.{{citation needed|date=September 2022}}