Altitude sickness

Altitude sickness or altitude illness is a pathological condition that is caused by lack of adaptation to high altitudes. It commonly occurs above 2,440 meters. The symptoms are headaches, fatigue, shortness of breath, nausea, unsteadiness, 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 cerebral edema[?] (fluid in the brain), 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.

Different people have different susceptibilities to altitude sickness. For some otherwise healthy people symptoms can begin to appear at around 1500 meters (5000 feet) above sea level. This is the altitude of Mexico City and Denver, Colorado.

The only real cure is to take the sufferer to a lower altitude. Altitude sickness may be prevented by ascending slowly and avoid strenuous exercise for the first day or two at altitude.

External Links

• Merck Manual entry on altitude sickness (http://www.merck.com/pubs/mmanual/section20/chapter281/281a.htm)
• University of Buffalo Reporter article on research into the cause of altitude sickness (http://www.buffalo.edu/reporter/vol29/vol29n30/n1)