Causes of Altitude sickness

Altitude sickness is a consequence of a lack of oxygen in the body. This lack of oxygen occurs because as the altitude increases, the atmospheric pressure decreases and there is less oxygen and nitrogen, meaning that the alveoli in the lungs cannot transport the necessary amount of oxygen to the blood. As well as a lack of oxygen (hypoxia), this process may produce dehydration, malaise and even death due to a pulmonary or cerebral oedema.   

There are some people who are more susceptible to altitude sickness, and there are also factors that affect it such as physical activity, speed of ascension or the initial altitude at departure.