Understanding Sleep Cycles and Their Impact on Health

2. The First Stage: Entering Sleep

The transition to sleep occurs much earlier than many people realize. Life stressors, excess stimulation, and environmental factors can keep the brain active even when the body is physically tired, preventing the transition from wakefulness to N1 sleep. However, once drowsiness finally takes over, alpha waves become the predominant pattern and slow the brain's activity, transitioning the body into the first stage of NREM sleep. N1 sleep is the shortest sleep cycle, taking an average of 1-7 minutes. Since this is the lightest stage of sleep, people can be awakened easily without mental fog or confusion.