Altitude sickness can occur when someone gets to a higher elevation too quickly. This sickness happens because the body is not able to adapt to the lower oxygen level and air pressure as someone climbs or walks to a higher altitude. Anyone can experience altitude sickness if they ascend too quickly.
Information. There are two primary risk factors for altitude sickness. These include vigorous exercise and ascending over 1,600 feet per day. The air at high elevations has less oxygen and this is what causes altitude sickness. People generally experience this sickness when they get to altitudes of at least 8,000 feet. When this sickness is mild, most people recover with fast treatment. In more advanced cases, emergency care is necessary, and the condition can be more difficult to treat.