Which condition describes a decrease in the number of respirations that may occur during sleep?

The condition that describes a decrease in the number of respirations, particularly during sleep, is bradypnea. Bradypnea refers to an abnormally slow respiratory rate, which can be normal during sleep for many individuals, as the body’s metabolic demands decrease and the respiratory drive is reduced. This can lead to fewer breaths taken per minute compared to wakefulness, where the respiration rate is typically higher.

In contrast, apnea refers to a temporary cessation of breathing, which might occur during sleep but is not characterized by a slower respiratory rate. Hypopnea denotes a reduction in airflow during breathing but doesn’t specifically indicate a slower rate of respiration; rather, it involves an incomplete breath. Tachypnea indicates an abnormally rapid breathing rate, which is the opposite of what's described in this context. Understanding these distinctions is key to accurately identifying respiratory conditions related to sleep and overall health.