Altitude sickness, also known as acute mountain sickness (AMS), is caused by lower levels of oxygen at high altitudes and a decrease in air pressure. Symptoms include nausea, vomiting, dizziness, light-headedness, fatigue, rapid heart rate and shortness of breath. Severe cases of altitude sickness may require hospitalization.
Treatments for altitude sickness include extra oxygen, descending to a lower altitude, or medication. Carbonic anhydrase inhibitor drugs like Diamox Sequels (acetazolamide er) are commonly used.