What is Stage 3 NREM sleep?

Stage 3 NREM sleep, also known as slow-wave sleep or deep sleep, is the third stage of non-rapid eye movement (NREM) sleep. It is characterized by slow, high-amplitude brain waves, known as delta waves, which make up at least 20% of the EEG.

During stage 3 NREM sleep, the body enters a state of deep relaxation and restoration, with the heart rate and breathing slowing down. The muscles are paralyzed, preventing the body from moving. This stage of sleep is essential for restoring the body and mind, as it allows for the repair and growth of tissues, as well as consolidation of memories.

Characteristics of Stage 3 NREM sleep:

- Slow, high-amplitude brain waves (delta waves)

- Deep relaxation and restoration of the body

- Slowed heart rate and breathing

- Muscle paralysis

- Essential for tissue repair, growth, and memory consolidation

Stage 3 NREM sleep typically occurs in longer periods during the first half of the night, with shorter durations in the second half. As the night progresses, sleep cycles tend to shift towards lighter stages of NREM sleep and REM sleep.