What term describes the deficiency in oxygen reaching the body's tissues?

The term that describes the deficiency in oxygen reaching the body's tissues is hypoxia. Hypoxia occurs when there is insufficient oxygen available for cellular metabolism, which is critical for the survival and proper functioning of tissues. This deficiency can arise from various causes, such as high altitudes, respiratory diseases, or even inadequate circulation.

In contrast, hyperoxia refers to an excess of oxygen in the tissues, which is the opposite of what hypoxia describes. Ischemia, while related, specifically refers to an inadequate blood supply to a tissue, leading to reduced oxygen and nutrient delivery. Osmosis is a different biological process altogether, focusing on the movement of water across cell membranes and does not pertain directly to oxygen deficiency. Understanding these terms is crucial, especially in medical settings or aviation where oxygen levels can significantly impact performance and safety.