Most people never have cause to think about the oxygen content in the air they breathe. At sea level, air consists of around 21 percent oxygen molecules, which is more than enough to keep your body supplied with this vital gas. However, as you travel upwards in altitude, the air becomes thinner, reaching levels of 14 percent at around 10,000 feet and 10 percent at 20,000 feet. This reduction in oxygen content can cause major discomfort as well as life-threatening conditions if you do not take the time to acclimatize yourself to a higher altitude.
Altitude Sickness
The most common symptoms associated with altitude sickness include headache, dizziness, nausea, and a general feeling of being out of breath. While most cases of mild altitude sickness pass of their own accord, a small percentage of these cases develop into high altitude pulmonary edema or high altitude cerebral edema. In HAPE and HACE, swelling and bleeding can occur in the lungs or brain, resulting in a heavy cough, exhaustion, difficulty breathing, loss of consciousness, and if left untreated, death. While many medications are available to treat the symptoms of altitude sickness, in many cases the best cure is a rapid descent.
Acclimatization
In order to reduce your chances of developing any form of altitude sickness, you should utilize a program of acclimatization. According to the Centers for Disease Control and Prevention, acclimatization to high altitude usually takes between three and five days, so if you are planning to spend time at high altitudes, you should schedule an appropriate stop and rest period before you reach 10,000 feet. A few days adapting to that level of reduced oxygen can help your body function at higher altitudes. Take your time ascending, avoid major exertion for the first few days of acclimatization, and avoid alcohol as much as possible to avoid problems.
Climbers
For those planning on high-altitude climbing excursions, the process is more involved, and the risks are higher. For instance, the air at the top of a mountain like Everest is thin enough that most people require supplemental oxygen merely to survive. Climbers should take extra precautions to acclimatize themselves as they ascend, keeping changes in altitude to less than 1,000 feet per day, and scheduling rest days for every 3,000 feet ascended. Ascending slowly and spending as much time resting in lower altitudes will help your body adjust to the conditions, as will staying hydrated throughout the process.
Treatment
If the symptoms of altitude sickness appear, you should go no higher until your condition has improved. Ascending while feeling ill can worsen symptoms and turn a mild case into a severe one. If symptoms do not improve with rest, you develop a severe cough with wheezing, or have difficulty concentrating, you should descend at least 2,000 feet as soon as possible. If symptoms still do not improve upon descent, seek medical help immediately.
