High Altitude Illness

With increasing numbers of people going to altitudes above 2500m, the "high altitude illness" has become a public health problem. The term "high altitude illness" describes the cerebral - i.e. acute mountain sickness (AMS) and high altitude cerebral edema (HACE) - and the pulmonary - i.e. high altitude pulmonary edema (HAPE)-syndroms, which occure in unacclimatised people travelling to high altitude. AMS is the most frequent problem and occurs already at altitudes above 2500m, whereas HACE and HAPE usually occur not until altitudes>4000m and >3000-4000m, respectively. The main focus of this article is on the differential diagnosis and the treatment of AMS, HACE and HAPE. Symptoms of AMS, which is usually harmless, can indicate a progress to the potentially lethal HACE. The treatment of HAPE differs from the treatment of any other cardiac edema. In every high altitude illness, the improvement of oxygen delivery has got the highest priority. The most important drugs are nifedipine for HAPE and dexamethasone for severe AMS and HACE, respectively.