Five Stages of Sleep: What's Up While You're Down?

In a typical eight-hour night, if you sleep well, you'll experience four or five 90-minute sleep cycles before waking up for the day.

Waking Stage
Your body prepares for sleep. You're awake in this stage, but very relaxed. Your eyes can be open or closed.

Sleep Stage 1: Drowsiness
At this stage--lasting anywhere from 10 seconds to 10 minutes--you transition from being awake to falling asleep. Your breathing becomes shallow and irregular. People often say they are half-asleep in this stage. You respond fairly quickly to disturbances since you're still aware of your surroundings.

Sleep Stage 2: Light Sleep
During this stage, your eye movements come to a halt, your blood pressure drops, and your muscles relax more. This is the actual beginning of sleep, because at this point you're no longer aware of your environment. read more...