Altitude Sickness
Altitude Sickness or Mountain Sickness, condition caused by reduced oxygen pressure at high altitudes, occurring in hikers as a consequence of relatively rapid ascent to high altitudes. Altitude sickness comprises a range of conditions, the most common being acute mountain sickness, which may be followed by two more critical conditions: high-altitude pulmonary edema or high-altitude cerebral edema. The exact cause of altitude sickness is unknown, although researchers believe insufficient oxygen may impair the function of the sodium pumps located in cell walls. Without sufficient oxygen, the pumps allow sodium levels within the cell to rise. As a result, excess water enters the cells, causing cellular swelling, or edema , a condition that is especially dangerous in the lungs and around the brain . The common symptoms of altitude sickness are headache , shortness of breath, sleep disturbances, and sometimes nausea. These symptoms, collectively called acute mountain sickness (AMS), appea