Question

How does altitude affect the human body?

Answer 1

Altitude is defined as the high altitude (8000 – 12,000 feet above), very high altitude (12,000 – 18,000 feet above), and extreme high altitude (18,000+ feet above). As people move higher in altitudes they experience some sickness as there are few changes that take place within the body.

Complete answer:
Many people tend to go for tourism at high altitudes which leads to some effect on their bodies. In normal conditions, the air that humans breathe has approximately 79 percent of nitrogen, 21 percent of oxygen, and many more. This composition of air remains constant at every altitude but the atmospheric pressure changes. Normally atmospheric pressure also known as barometric pressure is 760 mmHg (consisting of nitrogen, oxygen, water vapor, and carbon dioxide). Out of this atmospheric pressure, the partial pressure of oxygen is 160 mmHg (the number of oxygen molecules present in the given volume of air). At high altitudes, the partial pressure of oxygen decreases to 53 mmHg, this is because the oxygen molecules are away due to less pressure that pushes them together. Hence we can say that the availability of oxygen in the volume of air that we inhale is less, hence the body increases ventilation (increase in breathing).
Due to less amount of oxygen intake the muscle does not get enough oxygen which decreases muscle activity. After a few hours of altitude exposure, the loss of water increases leading to dehydration. It can also increase metabolism suppressing the appetite.
Some other altitude sickness includes headache, nausea, dizziness, etc.

Note:
People living in higher altitudes are said to have a larger lung capacity and can transport oxygen very effectively to the tissues. The effect caused due to the low partial pressure of oxygen on the body is known as hypoxia.