The Stages of Sleep

Sleep is a beautiful word and an exciting concept especially to those who suffer from insomnia.

Although you are at rest, not every part of your body is resting.

The brain in particular is sending out all sorts of signals, many of which are controlling the various stages of sleep you'll be undergoing. Eye movements and muscle activity change throughout the various stages of sleep too.

There are several known characteristics of sleep... we all look the same when sleeping... when a person is sleeping they lie down, their eyes are closed, the person doesn’t hear anything unless it is a loud noise that awakens them, and breathing becomes rhythmic and slow and in a distinguished pattern.

You will also notice when a person is sleeping the person’s muscles will relax completely and the sleeping person will turn over and rearrange their body once or twice an hour to keep blood flowing to all parts of the body.

There are five stages of sleep which have been identified and on a good night's sleep you pass through all of them, several times. Although there are 5 distinct stages, the first four stages are grouped together and classified as NREM or non-rapid eye movement. The fifth stage of sleep is known as REM sleep or rapid eye movement.

The different sleep stages are distinguished by the changes in brain wave activity that takes place. REM is also characterized by irregular but rapid breathing and heartbeat, a rise in blood pressure, increased brain activity and virtually no muscle activity.

NREM and REM sleep take place throughout the sleep period. The sleep that takes place during the first third of a night consists mostly of NREM while the sleep during the last third is mostly REM. Usually you will awaken from a REM stage.

Stage 1 -
is a transitional period. It consists of light sleep from which you can easily be awakened. During this stage you feel drowsy and begin to lose control over your muscles and your eye movements slow. During this stage, a sudden contraction or jerking of muscles can happen.

Stage 2 -
occupies nearly half of the sleep period. During this stage the eyes stop moving, brain waves slow, body temperature drops and heart beat slows.

Stages 3 and 4 -
are the stages during which the body is in a deep sleep. These 2 sleep stages are characterized by the presence of delta waves - brain waves that are extremely slow. Eyes and muscles are completely still during stages 3 and 4.

The REM stage takes place throughout the sleep period.
REM always follows a period of NREM sleep and accounts for about a quarter of the total sleep period.

The first REM occurs at the end of Stage 1 and lasts about 10 minutes. The final REM stage lasts longer, about an hour. If you sleep 8 or 9 hours, you'll typically experience REM sleep 4 or 5 times. You're able to dream during REM, too.

These sleep stages repeat throughout the sleep period and these repetitions are known as sleep cycles. Several sleep cycles take place during a single sleep period. As the sleep cycles progress through a sleep period, the amount of REM sleep increases.

Keeping the various stages of sleep from becoming disrupted is what results in better-quality sleep. But as we all know, there are some nights that getting uninterrupted sleep is much easier than others!