What does the term "hypopnea" refer to?

The term "hypopnea" specifically refers to a condition characterized by reduced airflow during sleep, typically leading to a notable drop in blood oxygen levels. This reduction in airflow can occur due to partial airway obstruction or other factors affecting respiratory function during sleep.

In a clinical context, hypopnea is often assessed in sleep studies where a decrease in airflow is measured, and the resultant decrease in oxygen saturation (desaturation) can have significant implications for a patient's overall health and quality of sleep. The essential aspect of hypopnea is that it is not a complete blockage (as in apnea) but rather a significant reduction that prompts physiological changes such as arousal from sleep and can lead to cardiovascular strain over time.

Understanding hypopnea is crucial in diagnosing and managing conditions like obstructive sleep apnea, where episodes of hypopnea can exacerbate sleep disturbances and negatively impact health outcomes.