What term describes impaired gas exchange leading to low oxygen levels in the blood?

The term that describes impaired gas exchange leading to low oxygen levels in the blood is hypoxemia. This condition specifically refers to reduced oxygen saturation levels in arterial blood, which can occur for several reasons, including issues affecting lung function, ventilation-perfusion mismatch, or diffusion impairments. Inadequate oxygen supply to the tissues can result, causing various physiological responses and potential organ dysfunction.

Hypercapnia refers to elevated levels of carbon dioxide in the blood, which is related but distinct from the low oxygen levels described in hypoxemia. Atelectasis relates to the collapse of lung tissue, which can contribute to hypoxemia but does not specifically define low oxygen levels. Respiratory alkalosis is a condition characterized by decreased carbon dioxide levels due to hyperventilation, and while it may be associated with changes in oxygen levels, it is not used to specifically describe low oxygen in the blood.