Fundamentals - Practice & Skills, part 7: Sleep, Sleep Disorders, and General Adaptation Syndrome


This article covers sleep basics, sleep disorders, and General Adaptation Syndrome. As with all of our videos, you can follow along with our Fundamentals of Nursing flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.


Sleep was once thought of as a passive and dormant state, but the more we learn about sleep, the more we know that it is a dynamic part of our lives. The brain is very active during sleep, and how well or poorly we sleep can affect our physical and mental health.

Circadian rhythm

The circadian rhythm is the internal biological clock that regulates the sleep and wake cycle of the human body. It regulates when we wake up in the morning and when we go to sleep at night. The circadian rhythm is affected by light exposure, environment, age, and illness or disease.

If the circadian rhythm is disrupted — for example, if you travel across time zones — this can induce an uncomfortable feeling known as jet lag. This is because your body's "clock" is out of sync with your normal circadian rhythm. Working an all-nighter can have the same effect as jet lag, and cause unwanted drowsiness at inopportune times during waking hours.

Stages of sleep

There are three stages of sleep, each one indicating a deeper level of sleep.

Stage 1

Stage 1 sleep is the transition from wakefulness to sleep. This usually lasts several minutes and, during this transition, the body's vital signs decrease naturally.

Stage 2

Stage 2 sleep is the light sleep before deep sleep begins. During stage 2 the body's vital signs continue to decrease.

Stage 3

Stage 3 sleep is deep sleep, when vital signs are at their lowest. In deep sleep, a person is difficult to awaken. A long, deep sleep allows us to feel refreshed when we wake in the morning.


REM stands for “rapid eye movement.” During REM sleep, brain activity increases again, meaning sleep is not as deep as in stage 3. In fact, the activity levels of the brain are the same as those when you’re awake.

REM sleep usually occurs about 90 minutes after falling asleep. During REM sleep, the eyes can be seen to move side to side rapidly, vital signs increase, and vivid dreaming occurs. It is difficult to wake a person in REM sleep, just as it is difficult when they are in stage 3 sleep. The difference is that in REM sleep, the vitals increase, whereas in stage 3 sleep, they decrease.

Common sleep disorders

People who struggle with a sleep disorder can experience a negative impact on their lives. A patient with a sleep disorder will find it affects their ability to recover from illnesses. It may also affect their ability to deal with pain and other symptoms of disease.

Three common sleep disorders are insomnia, sleep apnea, and narcolepsy.


Insomnia is a common sleep disorder that can make it difficult to fall asleep or stay asleep. It can cause you to wake up too early and to not be able to get back to sleep when waking in the middle of the night. Insomnia can sap a person's energy level and mood, and have a detrimental effect on their health, work performance, and quality of life.

Sleep Apnea

Sleep apnea is a breathing disruption that causes a person to stop breathing for a period of time while they sleep or breathe in an irregular pattern. When sleep apnea occurs, it can last at least 10 seconds and occur 5 or more times per hour. Sleep apnea can be either obstructive or central.

Obstructive sleep apnea is when sleep apnea is caused by an obstruction, for example, the upper airways become blocked by overly relaxed airway muscles or by the tongue or soft palate.

With central sleep apnea, the brain doesn't send the proper signals to the muscles that control breathing.


Narcolepsy is a chronic neurological disorder that affects the brain’s ability to control the sleep-wake cycle. A person with narcolepsy might experience uneven and interrupted sleep that can involve waking up frequently during the night. And while they may feel rested after waking, they will feel very sleepy throughout much of the day, to the point of suddenly, unwillingly falling asleep, even while eating or talking. This presents serious dangers should a person fall asleep while driving or operating heavy machinery.

Sleep hygiene

Sleep hygiene is a term for practices that promote improved sleep. It is important to teach your patients how to get better sleep. It is just as important that you learn how to get proper sleep too.

Here are some sleep hygiene best practices:

  • Follow a regular sleep schedule. That means going to bed and waking up around the same time each day. It is important to maintain regularity. Consider creating a routine you can follow before bedtime every night.
  • Sleep in a cool, dark, quiet room. The temperature in the room you sleep in should be cool (not cold), and there should be very little light or noise that could disrupt a good night's sleep.
  • Avoid naps in the late afternoon/evening. Taking a nap too late in the day can interfere with your nighttime routine, and delay the regular onset of sleepiness.
  • Avoid alcohol and caffeine later in the day. Either of these can affect your sleep patterns negatively.
  • Exercise regularly, but not within three hours of bedtime. Regular daytime exercise can help you fall asleep more easily at night. Exercising too close to bedtime can delay sleepiness and upset your sleep schedule.
  • Avoid large meals and the use of electronics before bedtime.
    • Large meals can cause indigestion or heartburn, and laying horizontally immediately after eating can cause acid reflux (gastric acid secretion).
    • When it comes to electronics, the blue light from screens can stimulate the brain, making it harder to fall asleep. Sleeping beside a blinking or beeping electronic device can cause undesired awakenings when you’re trying to sleep.

Stress: General Adaptation Syndrome

General Adaptation Syndrome (GAS) is what we call the physiological changes that occur during periods of stress, for example, during nursing school.

There are three stages of GAS: Alarm reaction, resistance, and exhaustion.

Alarm reaction stage

The alarm reaction is what happens first when something stresses us or we have a traumatic experience. It is the human "fight or flight" response.

Signs and symptoms of alarm reaction

Signs and symptoms of a person experiencing alarm reaction include elevated heart rate and blood pressure, elevated cortisol levels, and feelings of panic, frenzy, and stress.


Resistance is when the body attempts to normalize itself after the initial shock of the stressful event has subsided. The body gets used to the stress and tries to function normally again. That means that vital signs and hormone levels may normalize. But the effects of the initial shock may continue to manifest.

Signs and symptoms of resistance

The signs and symptoms of the resistance stage include poor concentration, irritability, and frustration.


The last stage is exhaustion. When the body finds itself under prolonged stress, it won't be able to resist or normalize. Exhaustion depletes the body’s resources and weakens the immune system.

Signs and symptoms of exhaustion

A person who is exhausted can suffer from fatigue, depression, anxiety, and possibly disease, because the stresses impair the normal function of the body's immune system.

It is important to educate your patients about these stages of General Adaptation Syndrome in order to help them learn to mitigate their stress levels. This in turn will help them recover faster.

Full Transcript: Fundamentals - Practice & Skills, part 7: Sleep, Sleep Disorders, and General Adaptation Syndrome

Hi, I'm Meris, and in this video, I'm going to be talking to you about sleep basics, sleep disorders, and General Adaptation Syndrome. I'm going to be following along with our Fundamentals of Nursing flashcards. These are available on our website, If you already have a set for yourself, you can follow along. I'm starting on card 62. Let's get started.

Okay, so starting off, we're going to talk about the circadian rhythm. So you'll hear this thrown around a lot in nursing school. The circadian rhythm is the natural wake and sleep cycle of the human body. So this what regulates why we wake up in the morning and why we go to sleep at night. So this is affected by light exposure, your environment, your age, and things like illnesses or disease processes.

So moving onto the stages of sleep. You'll see here, we have stage one through three. I would encourage you to look at these more in depth, but the ones that I really want to compare are going to be stage three and REM sleep.

One through three are kind of just going from light to deeper sleep.

But when you get to stage three, you're in very deep sleep, and the vital signs of your patient are at their lowest. So lowest vital signs in stage three,

compared to when we are in REM sleep. That stands for rapid eye movement. This is going to be about 90 minutes after you fall asleep, you're going to be in REM sleep, and this is where you're going to actually see the eyes moving rapidly, rapid eye movement. But the thing to note here is that vital signs are going to increase. This is also the phase of sleep where vivid dreaming occurs. So we're going to have difficultly to wake in stage three and in REM sleep, but vital signs will go up in REM sleep versus going down in stage three. Also very vivid dreaming in REM sleep.

Okay, so moving onto sleep disorders. Now, let me tell you, as someone who struggles with a sleep disorder and has since I was six years old, it really, really impacts your patient's life, and it impacts their ability to recover from illnesses, and it impacts their ability to deal with pain and symptoms.

So three big sleep disorders on here, and I would know them all. Insomnia, sleep apnea, and narcolepsy.

So I am a lifelong insomniac. I have difficulty falling asleep, but some insomniacs can fall asleep okay, have difficulty staying asleep, or both.

Narcolepsy, on the other hand, is going to be your patient with excessive daytime sleepiness, and they may be inadvertently falling asleep while they are awake.

Now, sleep apnea, this is going to be a patient who stops breathing for a period of time during their sleep, and they may have kind of an irregular breathing pattern during sleep.

So that is a very common one, and you'll see people using different devices to help them treat their sleep apnea, such as CPAP - continuous positive airway pressure - to help keep that airway open.

Now, here's my least favorite thing because I am very, very bad at following this advice. Sleep hygiene. So this very important patient teaching for you to tell your patients how to get better sleep. So in this instance, I'm going to say, "Do as I say, not as I do," because I have terrible sleep hygiene.

So the first is you want to follow a regular sleep schedule. Very important to maintain that regularity. Routine is important.

You want to sleep in a cool, dark, and quiet environment. So cool temperature, very little light, very little noise, best for sleep.

The other thing on here you're going to see is avoid naps in the afternoon. So when you're looking at those test questions, ask yourself, "Is this an early morning nap, or is this an afternoon nap?" Afternoon nap is going to delay my sleepiness in the future.

I'm going to avoid alcohol and caffeine later in the day. For me, personally, I do have to avoid caffeine starting at about noon, or else I will be up all night.

And then, exercise regularly, but there's a very important point on here. We don't exercise within three hours of bedtime. So exercise will help me sleep better, but not if it is within three hours of my bedtime. Okay, very important there. There's a few more, be sure to look them over.

Okay, now, we're going to talk about General Adaptation Syndrome, GAS. So this is the physiological changes that happen during periods of stress, like, I don't know, maybe nursing school.

So the alarm reaction is going to happen first. Alarm first, right? Sound the alarm. This is going to be your fight or flight response, right? This is going to be my heart rate. My blood pressure is going to go up. My cortisol levels are going to go up. This is where I'm going to feel really panicked, and frenzied, and stressed, right?

After that, I'm going to have the resistance phase. My body is going to get used to it. I'm going to be able to function again, right? My vital signs are going to normalize. My hormone levels might normalize some. But I may have some poor concentration, irritability, and frustration. I know we have all been there in nursing school. So I completely get it, and I feel like you completely get it too.

And then lastly, we have the exhaustion phase. Eventually, my body can't keep up anymore, right? Eventually, it's going to say, "I can't do this anymore," and we are going to tire out.

And this is where we're going to have fatigue, and depression, anxiety, maybe even disease because we might have impaired immunity from that prolonged stress. So very important that you educate your patients on this, and how to mitigate their stress levels. How to bring down their stress levels so that they don't end up affecting themselves in that way.

Okay, so that is it for basic sleep disorders and General Adaptation Syndrome. If that was a helpful review for you, please like this video, and I would love it if you leave a comment below, letting me know how you remember things or tell me about your experience when you have had nursing school stress. Did you reach the exhaustion phase? Or did you find a way to deal with your stress?

Okay, be sure to subscribe to the channel too because in my next video, we are going to be covering some really important stuff, like types of comfort care, the difference between hospice and palliative care. We're also going to talk about the stages and types of grief. So be sure to subscribe so that you're the first to know. Thanks so much and happy studying. Okay, all right. I can dig it. I'm very cool and hip with the kids, as you can tell.

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