What causes hypoxia?

Hypoxia is primarily caused by a decrease in the partial pressure of oxygen in the atmosphere, especially at high altitudes. As altitude increases, the atmospheric pressure decreases, which in turn reduces the partial pressure of oxygen available for breathing. This means that despite the presence of oxygen in the air, the body may not receive enough oxygen to meet its needs, leading to hypoxia. This condition can impair cognitive and physical functions, and at severe levels, it can be life-threatening.

While other factors like increased nitrogen content or high levels of carbon dioxide can affect air quality and body performance, they do not directly cause hypoxia in the same way that a reduction in oxygen partial pressure does. High humidity, on the other hand, can make the air feel heavy but does not significantly impact the oxygen levels needed for respiration at altitude.