altitude sickness

Discomfort caused by the lack of oxygen felt in high mountains, due to the progressive rarefaction of the air as altitude is gained. The main symptom of this disorder is a feeling of breathlessness and an increased heart rate, which can be accompanied by nausea, vomiting, and an intense headache. Altitude sickness can lead to a serious health problem - such as pulmonary edema - if high elevations are reached quickly, without adequate time for adaptation. It begins to manifest above 2500 m of elevation, although most people adapt easily to hypoxia up to the 3000 m mark. From there upward, the metabolism begins to show the effects of the oxygen shortage, which requires an adequate acclimatization period to be able to continue ascending. Altitude sickness is also known as mountain sickness, as well as AMS (acute mountain sickness) in medical jargon.