How to avoid altitude sickness

Altitude sickness (AMS) is a serious medical condition brought on by travelling too quickly to altitude, and/or performing physical exercise at altitude when unacclimatised.

Tolerance to altitude varies greatly amongst individuals, but a fit person who does not go too fast will not strain their cardiovascular system as much as an unfit person for the same amount of exercise and will therefore be at a lower risk of developing AMS. Even a very fit person however is still very likely to develop AMS if they trek to altitudes above 3500m without some days spent acclimatising or they walk too quickly.

Altitude sickness can occur in some people as low as 8,000 feet (2,400 metres), but serious symptoms do not usually occur until over 12,000 feet (3,700m). AMS is brought on by changes in the body caused by the reduction in air pressure at altitude. At 5000m the air pressure is reduced to 55% of that at sea level and at 6000m it is down to 49%.

This drop in pressure ha