Sarah, a 35-year-old professional, has been experiencing sleep issues for several months. She reports difficulty falling asleep, frequent awakenings, and feeling unrefreshed in the morning. A sleep study reveals that Sarah spends a lot of time in Stage 1 and Stage 2 sleep but has very limited Stage 3 (N3) sleep and almost no REM sleep. She often experiences hypnic jerks shortly after falling asleep and wakes up frequently, especially after entering Stage 2 sleep.

How might Sarah’s limited deep and REM sleep be contributing to her current physical and mental symptoms?

As a helpful reminder:

Stage 1 (Light Sleep): Transition from wakefulness to sleep; muscle activity slows down; may experience sudden muscle contractions (hypnic jerks); easily awakened.

Stage 2 (Light Sleep): Deeper than Stage 1; characterized by sleep spindles and K-complexes; body temperature drops, heart rate slows, and breathing becomes more regular.

Stage 3 (N3, Deep Sleep): Slow-wave sleep (SWS); deepest stage of non-REM sleep; brain waves slow down significantly; difficult to awaken; essential for physical and mental restoration.

REM (Rapid Eye Movement): Dream sleep; brain activity resembles wakefulness; vivid dreaming occurs; rapid eye movements; muscles are temporarily paralyzed; heart rate and breathing become irregular.