Adults typically go through about four to six sleep cycles in a full night's sleep, with each cycle lasting approximately 90 minutes. During these cycles, sleep progresses through various stages, including REM (Rapid Eye Movement) and non-REM sleep. These stages are essential for physical restoration, memory consolidation, and emotional regulation. The amount of sleep an adult requires may vary, but a full night generally encompasses multiple cycles, ensuring both restorative benefits and cognitive functioning.