In which stage of sleep does the body primarily repair and regenerate tissues?

The body primarily repairs and regenerates tissues during NREM stage 3 sleep, also known as slow-wave sleep (SWS) or deep sleep. This stage is critical for physical restoration processes. During NREM stage 3, there is an increase in blood flow to the muscles, which supports the repair of tissues and the growth of muscles. Additionally, the production of growth hormone is stimulated during this phase, further promoting healing and growth at the cellular level.

This stage of sleep is characterized by slow brain waves known as delta waves, and it represents the deepest level of sleep. It is during this time that the body can recover from fatigue, strengthen the immune system, and restore energy levels. Being essential for physical health, NREM stage 3 plays a significant role in overall well-being by facilitating critical restorative processes that are less pronounced in other sleep stages, such as REM or lighter stages of NREM sleep.