The stages of sleep can be broadly categorized into two main types: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. These stages cycle throughout the night in a pattern known as the sleep architecture. Here is an excerpt from sleep mechanisms
Excerpt: Sleep Mechanisms
Stage N3 (NREM 3): Also referred to as deep sleep or slow-wave sleep (SWS), this stage is characterized by the presence of slow brainwaves called delta waves. It is the deepest and most restorative stage of sleep, crucial for physical restoration, growth, and repair. Blood pressure drops, breathing slows down, and the body’s energy is replenished during this stage.