ALTITUDE SICKNESS

Altitude sickness, the mildest form being acute mountain sickness (AMS), is the negative health effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation.[1][2] People can respond to high altitude in different ways. Symptoms may include headaches, vomiting, tiredness, confusion, trouble sleeping, and dizziness.[1] Acute mountain sickness can progress to high altitude pulmonary edema (HAPE) with associated shortness of breath or high altitude cerebral edema (HACE) with associated confusion.[1][2] Chronic mountain sickness may occur after long term exposure to high altitude.[2]

Altitude sickness typically occurs only above 2,500 metres (8,000 ft), though some are affected at lower altitudes.[2][3] Risk factors include a prior episode of altitude sickness, a high degree of activity, and a rapid increase in elevation.[2] Diagnosis is based on symptoms and is supported in those who have more than a minor reduction in activities.[2][4] It is recommended that at high-altitude any symptoms of headache, nausea, shortness of breath, or vomiting be assumed to be altitude sickness.[5]