Hypoxia

Hypoxia, meaning “a deficiency in oxygen,” is the state of having a shortage of oxygen in the human body. For climbers, hypoxia occurs in the high mountains, as on the 8,000-meter peaks, where reduced levels of oxygen in the air lead to debilitating physical conditions, impaired judgment, and death. Most high-altitude climbers use bottled oxygen to ensure their survival. Some climbers, however, are better able to process oxygen, even at low levels, than most humans and are able to reach high summits like Mount Everest without the supplemental use of oxygen. Oxygen, taking into the body by breathing, is carried by blood vessels to the vital organs and limbs.