Sleep Stages and Cycles

Describe the stages of sleep and outline the order in which we progress through these stages during a typical night’s sleep.

APA

Sleep Stages and Cycles

Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.

Stages of Sleep
  1. NREM Stage 1 (Light Sleep)

    • This is the transition from wakefulness to sleep.
    • It lasts about 1-7 minutes.
    • Muscle activity decreases, and eye movements slow.
    • Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
  2. NREM Stage 2 (Deeper Light Sleep)

    • This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
    • Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…

Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.

Stages of Sleep
  1. NREM Stage 1 (Light Sleep)

    • This is the transition from wakefulness to sleep.
    • It lasts about 1-7 minutes.
    • Muscle activity decreases, and eye movements slow.
    • Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
  2. NREM Stage 2 (Deeper Light Sleep)

    • This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
    • Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…

Sleep progresses through several stages in a cycle that repeats multiple times throughout the night. The stages are divided into non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.

Stages of Sleep
  1. NREM Stage 1 (Light Sleep)

    • This is the transition from wakefulness to sleep.
    • It lasts about 1-7 minutes.
    • Muscle activity decreases, and eye movements slow.
    • Brain wave activity shifts from alpha waves (relaxed wakefulness) to theta waves.
  2. NREM Stage 2 (Deeper Light Sleep)

    • This stage lasts 10-25 minutes in the first cycle and lengthens in later cycles.
    • Brain activity slows, and sleep spindles (short bursts of brain activity) and K-complexes (sudden spikes) appear…