What does "hypoxia" refer to?

Hypoxia specifically refers to a condition where there is an insufficient supply of oxygen reaching the tissues of the body. This can occur at high altitudes where the air pressure is lower, which leads to reduced oxygen availability. In aviation, hypoxia is a critical concern because pilots need adequate oxygen to maintain cognitive functions and physical abilities while flying. Understanding hypoxia is essential for pilots to recognize its symptoms and effects, which can include impaired judgment, decreased coordination, and loss of consciousness.

The other options describe different physiological conditions but do not accurately define hypoxia. An excess of carbon dioxide in the blood relates to hypercapnia, while loss of hearing due to altitude pressure refers to barotrauma. Visual impairment caused by darkness is more related to the absence of light rather than oxygen deficiency. Recognizing these distinctions is key for pilots to ensure their safety and performance while operating an aircraft.