Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

At what stage of sleep is a person the most difficult to awaken?

1. Stage 1

2. Stage 2

3. Stage 3

4. Stage 4

The correct answer is: Stage 4

The correct answer is that a person is most difficult to awaken during Stage 4 of sleep, which is also referred to as deep sleep or slow-wave sleep. This stage is characterized by the presence of delta waves on an EEG, which indicate deep, restorative sleep. During this phase, the body is engaged in essential processes such as tissue growth and repair, and energy is restored. In this stage, the thresholds for arousal are significantly elevated, meaning it takes a greater stimulus to wake a person compared to the earlier stages of sleep. As sleep progresses through the cycles, particularly in deeper stages like Stage 4, the body becomes less responsive to external stimuli. This is why individuals in deep sleep may not easily awaken, even with loud noises or disturbances around them. Stage 3, which precedes Stage 4, also involves deep sleep but is less profound compared to Stage 4. Stages 1 and 2 comprise lighter stages of sleep; in these stages, awakening is much easier as individuals are more responsive to environmental cues.