Altitude Sickness Traditional Cache

Regardless of the altitude, air contains approximately 21% oxygen. At high altitudes, air density is reduced resulting in a decreased amount of oxygen inspired with each breath. When compared to sea level, the density of air at 18,000 feet is reduced by about 50%. This means that in order to obtain necessary oxygen at high elevations, one must breathe more frequently and achieve greater air exchange in the lungs.

Symptoms of altitude sickness (also known as acute mountain sickness) include headache, nausea, dizziness/lightheadedness, and fatigue. Oftentimes sufferers of altitude sickness appear pale, irritable, and exhausted. Altitude sickness can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE). HAPE and HACE are very serious and can result in death in a matter of hours if descent is not achieved and medical treatment is not obtained.

Altitude sickness affects approximately 25% of travelers to altitudes greater than 8,000 feet. Risk of development of altitude sickness is not affected by level of training or physical fitness. Generally, rate of ascent and level of exertion are predictors of risk. Altitude sickness can be avoided by acclimatization to high altitude, avoidance of early strenuous activity, and avoidance of respiratory depressants such as alcohol or sedating medications.

Treatment of altitude sickness is focused on increasing oxygen levels in the body. This can be achieved primarily by descent. Supplemental oxygen can also help treat altitude sickness. Headache symptoms can be managed with NSAIDs like ibuprofen or aspirin. A prescription drug called acetazolamide (Diamox) can be taken prior to ascent to help speed the acclimatization process and is useful for people who have previously developed altitude sickness or who plan to ascend quickly.