Altitude Illness - Army Public Health Center

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Altitude Illness

Photo of mountain range At altitude, there is decreased availability of oxygen in ambient (surrounding) air. This lowers the oxygen supply to the body, which can lead to altitude illnesses and reduced physical and mental performance. Altitude exposure may also increase the likelihood of other environmental injuries (e.g., cold injuries) or worsen pre-existing medical conditions.

Altitude	Meters (m) / Feet (ft)	Effects of Acute Altitude Exposure
Low	Sea Level – 1200m / 4000 ft	None
Moderate	1200-2400m / 4000-7870 ft	Mild altitude illness and decreased performance may occur
High	2400-4000m / 7870-13,125 ft	Altitude illness and performance decrements are more common and greater
Very High	4000-5500m / 13,125-18,000 ft	Altitude illness and decreased performance is the rule
Extreme	5500m / 18,000 ft - and higher	With acclimatization, humans can function for short periods of time

Topics

Altitude Effects on the Human Body

Common effects of altitude exposure on the human body, products to avoid at high altitudes, acclimatization

Altitude Illness and Environmental Threats

Information on altitude illness and environmental threats.

Topics

Altitude Effects on the Human Body

Altitude Illness and Environmental Threats

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