High-Altitude Illness | Causes & Risk Factors


What causes high-altitude illness?

You may have heard that the air is "thinner" at higher altitudes. This means that your body cannot get as much oxygen from the air when you are at a higher altitude. This happen most often at altitudes higher than 8,000 feet. This can cause problems for people who normally live at lower altitudes because their bodies aren't used to working on so little oxygen. If you stay at a high altitude for a long time, your body gets used to the low oxygen level, and you don't get sick from it.

The following are the 3 main types of high-altitude illness:

  • Acute mountain sickness
  • High-altitude pulmonary edema (also called HAPE), which affects the lungs
  • High-altitude cerebral edema (also called HACE), which affects the brain


Written by familydoctor.org editorial staff

Reviewed/Updated: 03/14
Created: 09/00