Altitude Sickness

Altitude sickness (also: acute mountain sickness (AMS) or altitude illness) is a pathological condition that is caused by lack of adaptation to high altitudes. It commonly occurs above 2,440 metres (8,000 feet). The symptoms are headaches, fatigue, shortness of breath, nausea, unsteadiness, loss of appetite, and sometimes even seizures and coma.

The most serious symptoms of altitude sickness are due to edema (fluid accumulation in the tissues of the body). At very high altitude, humans can get either pulmonary edema (fluid in the lungs), which causes persistent cough, possibly coma; or High Altitude Cerebral Edema (HACE), which causes nausea, headaches, or more serious brain malfunctions. These symptoms are potentially fatal. The physiological cause of altitude-induced edema is not conclusively established. For those suffering HAPE or HACE, dexamethasone may provide temporary relief from symptoms in order to keep descending under their own power.

Different people have different susceptibilities to altitude sickness. For some otherwise healthy people symptoms can begin to appear at around 1,500 metres (5,000 feet) above sea level. This is the altitude of Mexico City and Denver, Colorado.

Altitude acclimatization is the process of adjusting to decreasing oxygen levels at higher elevations, in order to avoid altitude sickness. Once above approximately 3,000 metres (9,800 feet), the general rule of thumb is to not ascend more than 300 metres (1,000 feet) per day to sleep. That is, one can go from 3,000 to 4,500 metres (14,765 feet) in one day, just that they should then descend back to 3,300 metres (10,825 feet) to sleep.

Acetazolamide may help some people in speeding up the acclimatization process and can treat mild cases of altitude sickness. Drinking plenty of water will also help in acclimatization to replace the fluids lost through the heavier breathing.

The only real cure once symptoms appear is to take the sufferer to a lower altitude. For serious cases of AMS, a Gamow bag can be used to reduce the effective altitude by as much at 1,500 meters (5,000 feet). A Gamow bag is a portable plastic pressure bag inflated with a foot pump.

External Links

• Merck Manual entry on altitude sickness
• University of Buffalo Reporter article on research into the cause of altitude sickness
• http://www.ismmed.org/np_altitude_tutorial.htm

DISCLAIMER

Please remember that Wikipedia is offered for informational use only. The information is in most cases not reviewed by professionals. You are advised to contact your doctor for health-related decisions.