How many stages of sleep are there, and how long is each stage?

Normal adults enter NREM at the beginning of sleep, from shallow to deep, about 60 90 minutes later, turn into rem, rem duration is only about 10 15 minutes, and then turn into NREM, so periodically alternate NREM and REM, 4 6 times a night, until you wake up.

Normal people sometimes have inactive eyes or only very slow fluctuations during sleep, which is a relatively long time; But sometimes the eyes move back and forth very quickly, and this period of time is relatively short, and the EEG changes differently at the same time as the eyes move slowly or quickly.

Stage 1 - light sleep, decreased muscle activity, occasional muscle twitches;

Stage 2 – slowing of breathing, heart rate, mild drop in body temperature;

Stage 3 – Deep sleep begins, and the brain produces slower δ brain waves;

Stage 4 - deep breathing, stable respiratory rhythm, limited muscle activity, brain waves dominated by δ waves;

Stage 5 – REM sleep, brain waves accelerate, enter a dream, muscles relax, heart rate increases, breathing is shallow and rapid.

There are different stages of sleep in which the muscles of the whole body relax when the person sleeps in this stage.

Human sleep is divided into three stages: light sleep, deep sleep, and moderate sleep, and different sleep will affect the quality of sleep in the body.

Normal adults enter NREM at the beginning of sleep, from shallow to deep, after about 60 90 minutes, it turns into REM, and the duration of REM is only about 10 15 minutes, and then it turns into NREM, and so it periodically alternates between NREM and REM, 4 6 times a night, and Sega until he is awake.

Normal people sometimes have inactive eyes or only very slow fluctuations during sleep, which is a relatively long time; However, sometimes the eyes move back and forth very quickly, and this period is relatively short, and the EEG shows different changes when the eyes move slowly or quickly at the same time as pure regrinding.

Sleep is divided into four stages: onset of sleep, light sleep, middle sleep and deep sleep.

1. Fall asleep.

It is the transition period between wakefulness and sleep, and people wake up very easily, accounting for about 10% of the total sleep time.

2. Light sleep period.

During this period, it is easy to wake up, and those who have difficulty falling asleep often wake up on their own, accounting for about 50% of the entire sleep period.

3. Sleep.

During this period, consciousness disappears, and it is not easy to wake up, and lasts about 1 hour after each sleep cycle.

4. Deep sleep period.

This period of deep sleep and awakening is quite difficult, lasting about 30 minutes in each sleep cycle, before entering REM sleep.