Sleep stages
... is the lightest period of sleep and is characterized by slow rolling eye movement. Not only your body but also your brain is getting relaxed; any sound or whisper may wake you up. This stage is only 5% of your sleep time. Next, you’re entering Stage II, known as The Light Sleep Stage. This point is considered the first true sleep stage and counts as about 50% of your total sleep. Additionally, Stage I and Stage II are just transitional because it takes only 30 minutes to complete these stages. In contrast with Stage I, in this point your eye movement disappear but your body has a little movement. Even though Stage II lasts twenty minutes, you have a lot of activities during this point: Your heart rate slows and your body temperature decreases, preparing your body for a deep sleep. Before you start dreaming, you pass through one Deep Sleep Stage (Stage III) in which you’re totally relaxed. Additionally, you have a slow, regular heart beat and respiratory rate. If somebody tries to wake you up, which is difficult, you are going to be kind of confused and slow to react. Nevertheless, it’s easy to go back to sleep. Moreover, dreams and sleepwalking are common during this stage; it’s well know too that the time spent in this stage of sleep decrease with age. This is the most important stage because if you don’t get enough in Stage III, you will be sleepy the next day. Finally, you enter Stage IV when you are in an intensive dreaming state and pass through REM (Rapid Eyes Movement...