What condition is characterized by decreased oxygen in the blood?

The condition characterized by decreased oxygen in the blood is hypoxemia. This term specifically refers to lower-than-normal levels of oxygen in arterial blood, which can result from various causes, including respiratory issues, circulatory problems, or high altitudes. Hypoxemia is measurable through arterial blood gas analysis and is critical to assess because it can lead to severe tissue hypoxia, where the tissues themselves do not receive enough oxygen to function properly.

Hypoxia, while related but distinct, refers to a deficiency of oxygen at the tissue or cellular level, which can occur even if blood oxygen levels are within normal ranges. Hypertrophy refers to the increase in the size of cells or tissues, typically in response to stress or increased workload, and does not relate to oxygen levels. Hyperoxia indicates an excess of oxygen in the tissues or blood, which is also not a description of decreased oxygen levels. Therefore, hypoxemia is the most accurate term for decreased oxygen concentration in the blood.