There are five distinct stages of sleep which humans pass through each time they go to sleep for the night. However, only one stage of sleep, REM sleep, standing for rapid eye movement, is the stage where dreams occurs. The other four stages are called non REM sleep stages.
The following is a simplistic explanation of the 5 stages of the sleep cycle
Stage 1 sleep normally lasts for about 5 to 10 minutes. You are not meant to stay in this stage for very long because this stage is simply meant as a stage to help your body and muscles relax. It is basically a transition stage to deeper sleep. It is the stage that you are in when you just drift off to sleep or the stage that you are come out of when you are just waking up.
Insomniacs who have trouble drifting off to sleep tend to sleep longer in this stage when they finally do.
Stage 2 sleep
Stage 2 sleep is still a transitional stage of sleep. It is considered light sleep. In this stage your body continues to relax, your mind, breathing, and your heart rate slows down. Your breathing and heart rate become even more regular and your temperature lowers in preparation for total relaxation and the deeper dream stages that will follow.
Stage 3 and Stage 4 sleep
These two stages are very similar. The brain waves in Stage 3 are called delta waves. If you were to measure them you would see that they are very slow waves, but sometimes there are some short fast brain wave bursts called beta waves. The Electroencephalography and the Electrocorticography will be able to measure the electrical charges of the brain during sleep.
A person who is woken from stage 3 dream sleep with feel groggy, disoriented, and confused for a while before their complete brain functioning comes back to them.
Stage 4 sleep
Stage 4 sleep is the deepest sleep of all. This stage of sleep is characterized by slow delta waves. In both Stage 3 and 4 dream sleep the stages normally last from 5 to 15 minutes however, the first real deep sleep in stage 4 can last up to an hour. Stage 4 sleep is the heaviest sleep stage and it is very difficult to wake someone up during this part of the sleep cycle. Stage 4 sleep is also the sleep phase where bed wetting in children occur and where sleep disorders such as night terrors will occur.
More about night terrors will be explained in a later section of this series.
In terms of health, this is the stage that is necessary for the body to repair, revitalize. and rejuvenate.
The older we get the less time we spend in deep sleep.
Stage 5 REM sleep
Stage 5 Sleep, REM sleep (Rapid Eye Movement) is also called active sleep. It is the stage in the sleep cycle where you will dream. REM sleep or dream sleep is called active sleep because your brain activity is as active as when you are awake. Not only does your brain activity increase in this stage of sleep, your blood flow and breathing return to normal.
Now even though you are revitalized during this period of the sleep cycle your muscles paralyze. Though that might seem counter intuition, it is nature's way of protecting us from any harmful physical activity if we should try to physically act out our dreams.
The first REM sleep occurs about an hour and a half after we drift off allow for each sleep stage to progress to the next. The first REM sleep is short lasting only about 10 minutes, but as the cycle repeats it can build up to about a hour a REM sleep cycle.
Some people believe that they do not dream, however everyone dreams. Many people do not remember their dreams. This is easily explained if we go back to stage 1 which is not a dream stage but the stage where we first drift off to sleep or the stage where we awake. It is possible to remember the last dreams we had during our sleep cycle if we awake during REM sleep or shortly thereafter.
Babies will be in REM sleep 50 percent of the time. REM sleep decreases with age. An adult usually spends about 25 percent of the dream stages in REM sleep and seniors spend less time than that.
Our ability to get a good night sleep, impacts upon our daily activity and our over all general and mental health. We will look at the link between learning and dreaming, and depression and dreaming as the series continues.
Tips For Getting a Good Night Sleep
Having trouble falling to sleep can be very frustrating and makes it harder to fully wake up once we do get to sleep.
Sticking to a sleep schedule is very helpful. Going to bed at about the same time each night and waking up about the same time each morning, even on the weekends can help regulate the body clock.
Avoid naps during the afternoon. A nap can cause a person to remain awake and not be able to go to sleep and the normal bedtime. If you take a nap during the day, make it a short nap, no more than 20 minutes.
Exercise daily, but not to close to bedtime. Exercise to close to bedtime can cause you to wake up and be more alert, which is not good right at bedtime.
A comfortable bed and bedroom is also essential for a good night sleep. If the bedroom is too hot, open a window, use the air conditioner before bedtime to cool it off, or better yet, crack the window open for fresh air. A humidifier can also help a bedroom be more comfortable. A humidifier can also help keep someone from snoring as it moistens the air.
Make sure your pillow and mattress are comfortable and does not cause you to have to move around during the night to get comfortable.
Before going to bed is not a good time to read e-mails, read disturbing news or go through the bills. Avoid things that will cause you stress and anxiety right before bed.
Avoid alcohol in the evening. Even though some people think a drink before bed relaxes them enough to go to sleep, but alcohol disturbs a healthy sleep cycle.
Avoid caffeine during the afternoon and evening, having a cup of coffee or an energy drink anytime after noon, can cause insomnia when it is time for bed.
If you cannot sleep after lying down, get up and do something relaxing like reading a book for a while. But avoid doing anything that will wake you up or cause stress.