Which gas is primarily responsible for the sensation of hypoxia at high altitudes?

At high altitudes, the primary gas responsible for the sensation of hypoxia is oxygen. As altitude increases, the atmospheric pressure decreases, which leads to a reduction in the partial pressure of oxygen available in the air. This decrease in oxygen availability means that less oxygen is bound to hemoglobin in the blood, resulting in inadequate oxygen supply to body tissues.

Hypoxia refers to a deficiency in the amount of oxygen reaching the tissues, and it manifests as various symptoms such as shortness of breath, dizziness, fatigue, and confusion. The body's response to reduced oxygen levels is a critical survival mechanism; it triggers physiological adaptations such as increased heart rate and faster breathing. Understanding the role of oxygen is essential for recognizing the importance of proper acclimatization and oxygen management when flying at high altitudes.