injuries poisoning
Altitude Illness
Key Points
About 20% of people who ascend to 2500 m (8000 ft) and 40% of those who ascend to 3000 m (10,000 ft) in one day develop some form of altitude illness, the most common form of which is acute mountain sickness (AMS). AMS causes headache plus fatigue, gastrointestinal symptoms (anorexia, nausea, vomiting), or persistent dizziness. High-altitude cerebral edema (HACE) causes headache, ataxia, and encephalopathy. High-altitude pulmonary edema (HAPE) causes dyspnea, decreased exertion tolerance, and dry cough initially which can progress to dyspnea with simple activities or at rest, profound fatigue, cyanosis and a cough productive of blood sputum in the more severe stages. Diagnose altitude illness based on clinical findings. Treat mild AMS with fluids, analgesics, sometimesacetazolamideordexamethasone, and by stopping further ascent. Arrange immediate descent for patients with HACE, HAPE, or very severe AMS. Prevent altitude illness by gradual ascent and use ofacetazolamide. 