When the Mountains Call . . .
. . . don't climb too fast! Lack of acclimatization and excessively rapid ascent are the main risk factors for acute mountain sickness, as Kai Schommer and Peter Bärtsch explain in this issue of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2011; 108 [49]: 839-48).
More and more tourists are climbing up mountains that are 5000 to almost 7000 meters high, such as Kilimanjaro, without any prior experience at high altitudes. The low oxygen content in the air can cause altitude sicknesses of various kinds.
For example, sudden vomiting and intractable headache may be the first signs of high-altitude cerebral edema. Persons who spend 48 hours or more above 4000 meters can suffer an impairment of consciousness that may progress to coma within hours. This disease is fatal if untreated. On the other hand, a noticeable loss of physical performance ability during the ascent and a dry cough are early manifestations of high-altitude pulmonary edema. Persons who fail to heed these warning signs and continue to ascend develop high-altitude cerebral edema as well.
No validated tests are available at present for the preventive assessment of a person's susceptibility to altitude sickness. The authors therefore recommend self-assessment of the following type: anyone who can hike for several hours at a normal pace in the Alps at altitudes of 2500 to 3000 meters ought to be able to tolerate similar exercise one altitude level higher while trekking, though perhaps at a somewhat slower pace.
http://www.aerzteblatt.de/v4/archiv/pdf.asp?id=116424