Altitude Sickness


Altitude sickness, also called acute mountain sickness, is a condition that affects people traveling at high altitudes, usually higher than 8,000 feet (2,400 meters) above sea level. The reduced air pressure and low oxygen levels found at high altitudes are the main causes of altitude sickness. Most cases of altitude sickness are mild and can be treated by descending to a lower altitude. However, severe complications can occur, so it important to be aware of symptoms so that the illness does not get worse.

Symptoms and diagnosis

Symptoms of altitude sickness range from mild to deadly, depending on how fast someone climbs and the amount of effort used in climbing. The majority of cases are mild. The most common symptoms of altitude sickness are similar to those of a hangover, with headache being the primary symptom. Altitude sickness may also cause tiredness, difficulty sleeping, nausea, vomiting, loss of appetite, dizziness, fast heartbeat, and shortness of breath with exertion.

Rarely, altitude sickness can cause more severe problems if a person continues to climb while experiencing symptoms. High altitude cerebral edema (HACE), or brain swelling, results in extreme tiredness, confusion, drowsiness, and loss of coordination or alertness.  Another complication is high altitude pulmonary edema (HAPE), or fluid in the lungs, resulting in weakness, cough, and shortness of breath while resting. Both cerebral edema and pulmonary edema can be deadly if not treated immediately.

Altitude sickness is diagnosed based on symptoms and ruling out similar conditions, such as dehydration, exhaustion, hypoglycemia, hypothermia, and neurological disorders.


Altitude sickness is caused by low air pressure and oxygen at high altitudes, most commonly above 8,000 feet (2,400 meters).  Everyone responds differently to high altitudes; however, people are more likely to get altitude sickness if they climb at a rapid pace, normally live at or near sea level, or have had altitude sickness before. Continue reading for Prevention and Treatment Information . . .

Pages: 1 2