Deep sleep, also known as slow-wave sleep or stage 3 of non-rapid eye movement (NREM) sleep, is a state of sleep characterized by slow brain waves, relaxed muscles, and a decreased heart rate. It is considered the most restorative stage of sleep, promoting physical restoration and cognitive functions such as memory consolidation and learning. During deep sleep, the body repairs and regenerates tissues, strengthens the immune system, and releases growth hormones. It is essential for overall health and well-being.
