Altitude sickness is caused by reduced air pressure and lower oxygen levels at high altitudes.
The faster you climb to a high altitude, the more likely you will get acute mountain sickness.
You are at higher risk for acute mountain sickness if:
- You live at or near sea level and travel to a high altitude
- You have had the illness before
Symptoms depend on the speed of your climb and how hard you push (exert) yourself. Symptoms range from mild to life-threatening. They can affect the nervous system, lungs, muscles, and heart.
In most cases, symptoms are mild. Symptoms of mild to moderate acute mountain sickness may include:
- Difficulty sleeping
- Dizziness or light-headedness
- Loss of appetite
- Nausea or vomiting
- Rapid pulse (heart rate)
- Shortness of breath with exertion