What physiological condition is characterized by the body receiving inadequate oxygen?

The correct answer, hypoxia, refers specifically to a condition where the body or a region of the body is deprived of adequate oxygen supply. This deficiency can occur for various reasons, including environmental factors like high altitude, where the availability of oxygen decreases, or medical conditions that affect breathing or circulation.

In a physiological context, hypoxia affects cellular processes since oxygen is crucial for cellular respiration and energy production. Without sufficient oxygen, cells cannot perform optimally, leading to symptoms that may vary in intensity depending on the degree of hypoxia. This can manifest as confusion, dizziness, or even loss of consciousness in severe cases.

The other choices address related but distinct physiological conditions. Hyperoxia refers to the presence of excess oxygen in the tissues or organs, which is not applicable in this scenario. Decompression sickness, commonly known as "the bends," occurs when dissolved gases in the bloodstream form bubbles as atmospheric pressure decreases, particularly during rapid ascent from deep dives; it’s more related to pressure changes than oxygen deprivation alone. Altitude sickness, while associated with reduced oxygen levels at high altitudes, encompasses a broader range of symptoms, including headaches and nausea, rather than the specific oxygen deficiency defined by hypoxia.