The risk of acute altitude sickness depends on the ascent speed, the height and the duration of the stay at high level. For some people, symptoms can occur in altitudes from 2000m. Experienced climbers can get symptoms just as often as the inexperienced. Short stays don’t cause symptoms.
Mild forms of altitude sickness cause headache, dipsomania, nausea and malaise. Severe acute altitude sickness can, among other symptoms, cause a change in the state of consciousness, vomiting, and oedemas.
Altitude sickness can be prevented by ascending to heights at a slow speed and by including days of rest.
Mild forms of altitude sickness are treated by staying 1-2 days in the same height and by using mild analgesics. When suffering from more serious symptoms, descent to lower heights is necessary.
Before initiating a journey that could involve stays in high altitudes, you should consult your doctor and get an evaluation of your health from which you may be prescribed drugs. If trekking in the mountains, you should also make sure that your guide is experienced in altitude sickness and is able to call for help in case of emergency.