Acute Mountain Sickness (AMS) occurs when there is an insufficient supply of oxygen at higher elevations.  The illness generally develops at elevations higher than 8,000 feet (about 2,400 meters) above sea level and when the rate of ascent exceeds 1,000 feet (300 meters) per day.  Symptoms of the illness range from a mild headache and tiredness to a life-threatening build-up of fluid in the lungs or brain at high altitudes.

The symptoms of acute mountain sickness can be prevented or minimized by gradually ascending (less than 500 meters/day) over several days to give your body a chance to acclimate to the higher altitude.  Medications such as Diamox and Dexamethasone have also been prescribed to treat the symptoms of AMS.

The following measures have been recommended by the American Heart Association to reduce the effects of AMS:

• Avoid strenuous activity for the first day or two.
• Drink extra fluid.
• Be careful of drinking alcohol. Its effect is magnified at high altitude.
• Your doctor may prescribe medication to help prevent or treat altitude sickness.
• If you have a heart or lung condition, consult your physician before going to high altitude.