During the past few years I had the opportunity to learn mountaineering and ice/rock climbing from a few storied guides. I even got to climb one of Canada’s sixteen 10,000′-plus peaks. Although neither of us developed any form of high-altitude illness the trip prompted me to research the disease. High-altitude illness encompasses a group of acute pathologies which affect the bodies of individuals not accustomed to altitudes over 2,500m (8,202 feet) above sea level. These are acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). AMS is far more common than HAPE and HACE with the latter two occurring in less than 0.1 to 4.0% of ascent cases. AMS equally affects both men & women as well as paediatric & adult patients. Strangely individuals over 50 seem to have a lower risk of developing AMS. I will reference Basnyat & Murdoch, 2003 (free public access) as well as the Merck page on Altitude Sickness. See also BaseCamp MD.
Signs and Symptoms
We in Canada actually contributed to the diagnosis of AMS! The Lake Louise Consensus Group defines AMS as a new onset headache, in an unacclimatized person, who has recently travelled above 2500m as well as at least one of the following: fatigue, nausea, vomiting, loss of appetite, dizziness, and/or sleep disturbances. The symptoms typically begin 6 to 10 h after ascent and spontaneously subside after one to two days. Continue reading