Which two physiological stresses are commonly encountered at altitude?

Which two physiological stresses are commonly encountered at altitude?

• A. Hyperoxia and dehydration.
• B. Hypoxia and fatigue.
• C. Barotrauma and motion sickness.
• D. Decompression sickness and hypothermia.

Answer: (B)

When you ascend to higher altitudes, the air is thinner, so the partial pressure of oxygen in the lungs falls. That reduces the amount of oxygen that gets into the blood and ultimately to tissues, creating hypoxia. With less oxygen available for energy production, the body’s performance declines and fatigue sets in more quickly, making tasks feel harder and cognitive function can be affected. Fatigue is a common companion to hypoxia because tissues aren’t receiving the oxygen they normally rely on for efficient energy generation. Other conditions listed—like barotrauma, motion sickness, or decompression sickness—are not as routinely encountered as primary stresses in typical altitude exposure, and while hypothermia can occur, the combination most characteristic of high altitude is hypoxia paired with fatigue.

When you ascend to higher altitudes, the air is thinner, so the partial pressure of oxygen in the lungs falls. That reduces the amount of oxygen that gets into the blood and ultimately to tissues, creating hypoxia. With less oxygen available for energy production, the body’s performance declines and fatigue sets in more quickly, making tasks feel harder and cognitive function can be affected. Fatigue is a common companion to hypoxia because tissues aren’t receiving the oxygen they normally rely on for efficient energy generation. Other conditions listed—like barotrauma, motion sickness, or decompression sickness—are not as routinely encountered as primary stresses in typical altitude exposure, and while hypothermia can occur, the combination most characteristic of high altitude is hypoxia paired with fatigue.