Ascending to, or being at, high altitude may cause high altitude illness (HAI). HAI includes acute mountain sickness (AMS), high altitude cerebral edema (HACE) and high-altitude pulmonary edema (HAPE). HAI is caused by exposure to the hypobaric hypoxic environment, and it can lead to life-threatening physiologic changes.
Travel to high altitude may also exacerbate certain pre-existing medical conditions. It is often possible to prevent HAI by ascending slowly and allowing the body to adjust during a gradual ascent. Serious complications of high-altitude disease can be avoided by appropriate preparation, early surveillance of symptom onset, and aggressive treatment of disease. Normally, the most appropriate treatment in all altitude illnesses is to descend.
These clinical practice guidelines are adapted from the Wilderness Medicine Society (WMS) guidelines given that military operations may not allow forces to conduct the WMS recommended treatment. The WMS guidelines can be found at: https://wms.org/magazine/magazine/1191/WMS_Clinical_Practice_Guidelines/Default.aspx