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By: Kent Caylor, RPSGT on August 16th, 2017

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The Effects of Night Shift Work on Sleep!

night shift work

effects of night shift work on sleep

What are the effects of night shift work on sleep?  Let’s look at why we need sleep and when to get the best sleep.  We'll also explore whether Shift Work Sleep Disorder is a real disorder, and answer the question, 'Is sleeping during the day really all that bad?'


Why do we need sleep?


We used to believe that sleep was a state of unconsciousness, where nothing really happened. We now know, however, that sleep performs a number of necessary functions. One of these is memory consolidation. There are also physical benefits to sleep beyond just getting rest.


In fact, fascinating studies are being conducted that show how learning is consolidated during REM sleep, specifically when it's preceded by SWS.  Even problem solving and learning can be enhanced by sleep in general. 


But just how does this thing called sleep happen? How is it regulated?  And how does it get out of whack?


Let's take a look at that.


Our Circadian Rhythm


To begin with, there are a number of biological clocks in you that regulate various functions. These are controlled by a master clock that keeps them all in sync. It's called the Suprachiasmatic Nucleus (SCN), and is located in the Hypothalamus.


The SCN regulates your circadian rhythm, which controls your sleep-wake cycle, and works on a roughly 24 hour period. This rhythm is regulated internally, but external cues such as light can influence it as well.

 circadian rhythm

When it's dark, and/or you close your eyes, a chemical called Melatonin is released. This is your bodys natural sleep aid; which is why sleeping when it's dark produces better sleep. But it's a bit more complicated than that, because sleeping odd hours also causes your circadian rhythm to get out of sync; resulting in a condition known as Shift Work Sleep Disorder.  But just what is Shift Work Sleep Disorder anyway?


Is Shift Work Sleep Disorder real?


Shift Work Sleep Disorder, or SWSD,  is defined by excessive sleepiness while up at night, and insomnia when trying to sleep during the day (isn't this a normal reaction?). It affects people whose work requires them to sleep at times other than at night.


As stated earlier, when you sleep nights, your circadian rhythm is in sync. This is your natural sleep time. However, being up all night, and sleeping during the day disrupts that cycle. That's because you're trying to change one of your bodys natural functions, which causes your circadian rhythm to become dysregulated.


This is also what causes Jet Lag. However, jet lag can be 'cured' by just returning to your nightly jet lagsleep schedule in your own time zone; while your work schedule is putting you in extreme chronic Jet Lag. But does that make it a disorder? And if so, what's the best way to treat it?

Well, let's first take a look at some of the effects of this circadian dysregulation.


Effects of daytime sleep


There are many studies that show a correlation between certain diseases, and shift work. Some of these diseases include: Increased cardiac mortality, mental disorders, such as Alzheimer's, and even certain cancers

If you work the night shift, You're even more at risk for disease than those who are sleep deprived

Circadian dysregulation can worsen inflammatory disorders, lowers metabolism and increases blood sugar levels.  Even without the disease connection, day sleep isn't as good a quality of sleep as night sleep. This is most likely due to reduced Melatonin output during the day.


Also, sleeping odd hours can literally damage your DNA. Here's how:


There's a chemical called 8-OHdG. This is a known biomarker of oxidative damage to DNA, and is present in your urine. Studies indicate a reduced level of this chemical in night shift workers; probably due to reduced Melatonin output. This reduced level translates in to a lowered ability for your body to fend off any damage to itself.  So then, sleeping at odd hours can cause damage right down to the molecular level. Therefore, it can be classified as a disorder. But what is the best treatment for it?


First, let's look at some variables.


Things you can control


Besides using a good pillow and keeping the room temperature  comfortable, keep the following in mind:

  • Do as many healthy things as possible, such as exercise. More on this later.
  • It's best to keep the same sleep schedule, although, that might not be practical for those of us who work nights.
  • Maintain a good sleeping position (not so easy when you're sleeping). More on this later.
Keep people from knocking on your door--Putting a sign on your door letting people know you're a night shift worker and are sleeping should stop them.
  • Use room darkening shades.
  • Don’t work nights (unless you have something to say about it).

Things you can't control

  • Damage to your DNA and other body organs.
  • Neighbors mowing their lawn right outside your window (or at least that's what it sounds like).
  • Other daytime annoyances.
  • Other people in your house.
  • People knocking on your door -They might even with a sign telling them you're asleep (?)
  • Working nights (unless you have something to say about it)


Next, we'll look at some treatment options.


Conventional Treatment


To help stay awake, there's Provigil and Nuvigil. And for sleep, benzodiazepines, hypnotics, and certain antidepressants. Consult your Doctor for more information on these, and other medications.

As a side note, at least some studies show that smoking Marijuana attenuates mood and sleep disruptions, which is good.  However, it also attenuates performance, which isn't so good.


Alternative Treatment


If you must work a rotating shift, then going from morning to afternoon to nights at 2-3 day intervals works well. Although a straight night shift is better yet; if you have anything to say about it, that is.  However, switching to straight day shift showed the best improvement in well being. 

Also, the proper use of artificial light, when timed right, can reset your circadian pacemaker as much as 12 hrs in 2-3 days.1 


Exercise improves sleep quality; but, it's best to exercise soon after you wake up. Although 'mellow' stretching exercises can be a good way to relax right before bedtime.  Some good exercises include aerobics, walking, cycling, stair climbing/ellipticals, swimming, and jogging. Do the 'talk test'.  In other words, exercise at a moderate pace for about 30 minutes, making sure you can talk while doing so.

Finally, don't neglect proper sleep position.  Back sleep is actually the best, as it keeps your spine in good alignment.  Sleeping on your stomach is bad because you have to turn your head and shift your back in order to breathe. This puts stress on the muscles, ligaments, and discs in your neck, and could cause injury.



We've looked at why we sleep, the best time to sleep, and the effects of shift work on sleep. We also covered some things you can do to alleviate some of the negative effects of day sleep; as well as some conventional and alternative forms of treatment. And while not exhaustive, I hope you find this information helpful.

 Sleep Technology Terms and Definitions


1  Czeisler CA, Kronauer RE, Allan JS, et al. . Bright light induction of strong (Type 0) resetting of the human circadian pacemaker. Science, 1989; 244:1328–33.