What condition is characterized by a decrease in arterial oxygen supply?

The condition characterized by a decrease in arterial oxygen supply is hypoxia. This term specifically refers to a state in which there is inadequate oxygen available to tissues and organs, which can result from various factors, including reduced oxygen levels in the blood or impaired delivery of oxygen to the tissues.

In the case of hypoxia, the arterial oxygen supply is insufficient for the body's needs, which can lead to cellular dysfunction and systemic effects. Understanding hypoxia is crucial because it emphasizes the importance of oxygen in maintaining cellular metabolism and overall health.

Other conditions mentioned pertain to different physiological states. For instance, ischemia relates to a decrease in blood flow to tissues, potentially leading to hypoxia as a secondary effect but is not itself defined as decreased oxygen supply alone. Hypercapnia refers to an excess of carbon dioxide in the blood, often resulting from respiratory issues rather than a direct decrease in oxygen supply. Hyperoxia involves an excess of oxygen, which is the opposite of what hypoxia denotes. Hence, hypoxia is the most accurate description for a decreased arterial oxygen supply.