Stages of Sleep, Sleep Cycles & REM
Sleep is a strange thing; the average person tends to spend one third of their life asleep. However, despite this there doesn’t seem to be any evolutionary advantage to sleep. Here, we will discuss the different stages of sleep, sleep cycles, non-REM and REM sleep and sleep paralysis.
Different Stages of Sleep and Sleep Cycles
During an average night’s sleep, this is around 8 hours for adults, your body moves through multiple cycles of sleep. Each cycle will include the different stages of sleep, these stages include 1 to 4 and REM (Rapid Eye Movement). It is during REM which your brain will start to heal itself and ‘flush out the waste’. REM is also the stage in which you will experience dreams it accounts for up to 20% – 25% of total sleep time for adults. But we will talk about REM a little later, for now we will examine the various cycles and stages of sleep. A full cycle of sleep typically takes around 90 to 100 minutes, each stage within the cycle will take around 10 minutes give or take 5 minutes. As the night progresses your REM sleep will start of short and will progressively get longer as you move into deep sleep.
Examining the Stages of Sleep
The first stage you are drifting in and out of sleep, you can easily be awakened by the sightless touch or sound. Throughout this stage, your body will start to decrease muscle activity and lower the heart rate. Some effects of the body decreasing muscle active will include falling sensations, slight involuntary twitches and jolts, these are called hypnic jerks. During this stage of sleep your body is preparing to progress into deeper sleep. Stage 2: Moving into deeper sleep, eye movement begins to stop, brain activity begins to slow down. Your body temperature will also begin to drop as your body is moving into maximin efficiency mode.
Stage 3 during this stage of sleep, brain activity is now very slow, brain activity is very low, waves called delta waves are intermixed with smaller and fasters waves. This is considered deep sleep, within stage 3 you may experience sleep walking, sleep talking or night terrors. These are called parasomnias, these take place between non-REM and REM sleep. Moving on to stage 4, brain activity consists of almost entirely delta waves. Waking up during this stage will leave you feeling tired, rough and unbalanced.
What is REM (Rapid Eye Movement) Sleep?
REM sleep is the main stage of sleep, this accounts for 20% to 25% of the total sleeping time. The length of REM sleep will grow larger the longer you have been sleeping. REM gets its name from the act of the eyes moving from side to side while you sleep. This can be observed using technique called electrooculography (EOG). Science still does not fully understand the purpose of body moving the eyes from side to side during this stage of sleep. It is thought that your body is reacting to images caused by dreams. This act is not consistent through REM sleep either which further adds to the mystery.
During REM sleep muscles become completely paralyzed and un responsive. This is the reason some people may experience sleep paralysis, this is the result of the brain waking up before the rest of the body has time to catch up, you will experience being conscious but being completely unable to move. But we will explore this in more detail later. This is unlike non-REM sleep where the muscles become more and more relaxed as sleep progresses. The reason in which the muscles are completely paralyzed is the consequence of brain activity being reduced to just a few very small waves, the brain functions which control muscle movement are completely suppressed, this phenomenon is called atonia. The only muscles that continue to function during this stage apart from the movement of the eyes are vital operations such as the heart and diaphragm.
It is common for the body to be sexually aroused during this period a male’s penis and a female’s clitoris may become aroused during this stage of sleep. It is a common misconception that people wake up feeling aroused must have been dreaming about a sexual experience, this is not the case. The body may be sexually aroused regardless of whether it was dreaming about sexual experiences or not. During this stage the breathing will also begin to change, breathing starts to increase in frequency. The body will start to increase the heart rate and blood pressure to levels that are like being awake. Through this stage of sleep the body’s core temperature is poorly regulated and generally starts to head towards the temperature of the room. This is the reason you may sometimes wake up feeling cold.
What is Sleep Paralysis?
“Sleep paralysis is a temporary inability to move or speak that occurs when you’re waking up or falling asleep. It’s not harmful and should pass in a few seconds or minutes, but can be very frightening.” – NHS.
Lots of people around the world, of all ages will experience sleep paralysis at some point in their life. Some people may only experience this once or twice in their life and some people may experience this weekly. However, sleep paralysis is generally more prevalent in teenagers and young adults. The fundamental symptom of sleep paralysis is being fully conscious just after waking up and temporarily being completely unable to move or even talk. This tends to only occur when waking up but it can happen just as your falling asleep.
During sleep paralysis, some things people can experience are the feeling of being scared from a lack of understanding of what is happening, some people may hallucinate or have a sensation that somebody or something is the same room as you. These hallucinations or sensations are commonly very negative, people feel as if they are there to hurt them. Each episode can last around a few seconds to a few minutes. However, it’s common for the paralysis to ware off after just a few seconds.
Sleep paralysis tends to normally occur during REM while you are awake. Again, REM is one of the most dominant stages of sleep. Throughout this stage of sleep its considered that your body prevents muscle movement to protect itself from self-harm while dreaming. However, science is yet to find out why REM sometimes occurs while you are awake. Some causes of sleep paralysis can include: not getting enough sleep, irregular sleeping patterns, a family history of sleep paralysis, sleeping on your back and narcolepsy.
In the video above, Brian Sharpless a clinic psychologist at Pennsylvania State University states the experience of sleep paralysis as falling asleep or waking up and finding that you are completely paralysed. However, you have some degree of conscious and awareness, your eyes are still able to move around and function normally. Brian said, “this is often a terrifying experience for people that are suffering from it, not only from the paralysis but because of the hallucinations.”. While experiencing sleep paralysis there are generally three types of hallucinations, let’s explore these:
First, there is the intruder which is the sight/sensation of evil presence approaching. Second, the incubus something pressing on your chest, chocking or assaulting you. Finally, levitation is the sensation of being lifted off the bed and being transported elsewhere. If you put these types of hallucinations together, you may find some familiar sound UFO stories. Brian said, “I think all three categories are consistent with what people who report being abducted by aliens experience.”.
Why sleep is Important?
Sleep is very important as it makes up a big portion of a person’s ability to stay healthy and happy. Making sure to get the right amount of good quality sleep during the right hours will help to support against mental illnesses, physical health and general wellbeing. For children and teenagers getting enough sleep is vitally important is it helps growth and development.
The damage caused by not getting enough sleep can cause temporary/permeant metal suffering. You just need to watch Twitch streamers as they stay up for days straight, look at their ability to talk and function at a basic level diminish. The effects of sleep deficiency can occur in a second or they can develop slowly overtime. A lack of sleep can affect your mental capacity, your reaction time, your ability to take in and retain new information/skills and it can affect how you socializer and communicate with others.
Hopefully this article has cleared up many questions you may or may not of have about, the stages of sleep, sleep cycles and what is REM sleep. Not getting enough sleep can cause long term issues, if you are somebody that has a hard time falling asleep there are lots of different things you can try to help you get in the bedtime mood. For example, stay away from electronic devices for an hour before bedtime, stay away from caffeine for at least 4 hours before bed, dim the lights an hour before bedtime, read a book and definitely no eating in or working from your bed. Your body will need time to relax from the day, it is also very important for your body to only associate your bed with sleeping, therefore It is so important not to eat or work in your bed. However, if after doing all these you still cannot sleep then consider contacting a medical professional.
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