How does altitude sickness work?
During the trek it is likely that all climbers will experience at least some form of mild altitude sickness. It is caused by the failure of the body to adapt quickly enough to the reduced level of oxygen in the air at an increased altitude. There are many different symptoms but the most common are headaches, light-headedness, nausea, loss of appetite, tingling in the extremities (toes, fingers) and a mild swelling of ankles and fingers. These mild forms are not serious and will normally disappear within 48 hours.
