Altitude sickness is characterized by headache, nausea, shortness of breath on exertion, tachycardia and fatigue. In very rare circumstances, it can cause pulmonary edema or cerebral edema.
In order to avoid or minimize the symptoms of altitude sickness, the traveler from sea level has to take it easy. Upon arrival to the high altitude location, rest, walk slowly, and take deep breaths. The tourist must eat lightly and allow one or two days for proper acclimatization (getting used to the new environment). True acclimatization does not complete until 2 or 3 weeks, however, there is never so much time during vacation. A strategy that some travelers employ is to travel to the desired destination in a stepwise fashion, stopping in intermediate altitude towns prior to the arrival to the high altitude place.
Finally, there are medications that physicians are familiar with and that may help. Travelers should contact their respective doctor for this purpose.
Marco A. Ramos MD