[Is altitude good for health?].

Health at altitude depends on the success of functional adjustments. Only the success of the short-term adjustments including increased tidal volume, acceleration of circulation, centralization of blood volume, hemoconcentration and adjustment of de diuresis to reduce cardiac volume overload render acclimatization possible. During these long-term adjustments, which always remain incomplete at altitudes above 2000 to 3000 m, mainly the cardiovascular economy and the respiratory efficiency are improved. Failure of the short-term adjustments excludes acclimatization and may be due to reduced physical capacity or to excessive physical activity (too fast too high). It is associated with sympathetic cardiac volume overload, central hypoxia, antidiuresis and distress which result in acute mountain sickness. Health at altitude may be preserved by moderating the ascent, the duration and the physical activity there.