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Effects of Shift Work On The Body – Is It Manageable?

Effects Of Shift Work On The Body – Is It Manageable?

I worked shift work for 9 years and can say with certainty, that shift work had a huge impact on my body, hormones and mental state. I rotated between day shifts and nights shifts and my shifts were 12 hours long. On top of the long shifts, the job was inherently very stressful and required that I was attentive and alert at all times.

Although I was able to adapt quickly to the lack of sleep and work many night shifts after having been up all day, I was never able to sleep during the day. I am sure those who can at least get some shut-eye during the day have an advantage and it would help with overall health, but as we will learn further in this article, working night shifts long-term, will still impact your health even if you manage to sleep during the day. I continued to increase my “sleep debt” with continuous days of  not being able to sleep before and after a night shift.

So basically I would work two 12 hour day shifts (from 6 am to 6 pm) and then I had to switch over to two 12 hours night shifts (from 6 pm to 6 am). So when I would get to bed the evening after my second day shift, I would be up at 7 am the next day because my body had woken up at 4 am the 2 previous days and could not adjust more than that. I tried it all, trying to stay up as late as I could on my second day shift but I would still be up really early on my first night shift. To make matters worse,  because I could not nap, I would get to bed at around 730am the NEXT day after my first night shift, basically having been awake for over 24 hours.

The fact that I was over-fatigued and high on adrenaline, is what probably kept me from ever being able to fall into a deep sleep after my first night shift. What made things worse was during the summer months because I would hear the birds chirping and see the sun rising on a beautiful summer day.  I could just not turn off my mind and sleep peacefully.

If I was lucky, I would maybe get 6 hours of sleep after my 1st night shift but remember, I had been awake for over 24 hours. If this were to happen once in awhile, this is OK for the body as it would be a short term stress for the system. Our bodies are flexible and can adapt and regulate. But after months and then years, this state of extreme fatigue and working against the bodies natural hormonal and circadian cycle is very detrimental on the body.


Funny thing was that although the first year was difficult to get through a 12-hour night shift after having been up all day, my body and mind reached a point where it eventually just became normal. It was like I developed the capacity to function on very little sleep and although this was not a good thing for the body, I felt empowered! Crazy right?

All I could see was that I was able to still train every day, I still had a social life, I would be able to have personal time to get things done before my night shifts and I would even pick up extra shifts on my subsequent 4 days off! Why? Again, I just saw the positive: that I was able to travel more because of the extra time and money accumulated.

What did I not see or chose to ignore? I went from having very irregular periods (before starting shift work) to NO menstrual cycle, I was very irritable and impatient and more emotional than usual. Now regarding my menstruation ladies, I suffer from PCOS and I did not know that until this present day. This is because PCOS is often associated with obesity and I was and still am lean due to my active and healthy lifestyle choices. So I was always told I did not have regular periods because I trained too hard.

Well I started shift work in 2008, stopped shift work in 2017, and I am writing this blog in 2020 and guess what? I still do not have a period. A natural pregnancy will not be possible for me and even after many rounds of estrogen and progesterone treatments to try to re-set my cycle to even an irregular one, has failed each time.

What is shift work?

Shift work is any shift that involves working outside of the traditional 9 am to 5 pm hours. Shift work can be late evenings, very early mornings and can be static or rotational.

Benefits of Shift Work – Are there really?

Shift work is a necessity in many industries and both men and women are equally implicated in shift work today. Shift work makes it possible to provide services 24/7 for many important services especially the health and emergency fields.

In some cases, people prefer shift work because:

a. It pays more;

b. Facilitates child care with their partner;

c. They can juggle 2 jobs if necessary;

d. It is the “nature” of the job and they love what they do as a profession.

Many reports state that approximately 25% of people work shift work today and over 30% of these people are diagnosed with serious health issues

What Does Shift Work Do to the Body?

1. Shift Work Disorder

According to the National Sleep Foundation, symptoms of sleep disorder are:

a. Feeling drowsy at work;

b. Not feeling like yourself when at home with the family;

c. Fall asleep on shift;

d. Not productive at work and slow to make decisions;

e. Experiencing broken sleep;

f. Irritable or moody;

g. Work schedule is creating problems in personal life with family and friends.

This type of disorder starts during the early signs of health related issues and are the cues we need to recognize before long-term effects start to occur.

Why Does Shift Work Effect Us?


Circadian Rhythm: We have all heard about this “clock” that our body follows. The body is internally regulated to control our sleep-wake cycle over a 24 hour period. This clock performs important bodily functions and therefore interrupting this cycle will cause an imbalance in hormones and difficulty sleeping.

The problem is that a large part of the circadian cycle is triggered or responds to external cues such as light and temperature. This is how your circadian cycle adjusts to different time zones. This explains why people who work regular nights shifts and manage to get very good sleep during the day, still feel drowsy during their night shifts. This is because the circadian clock is fighting against your sleep pattern which goes against the normal cycle. The circadian cycle will never adjust because it is largely dependent on the real time of day and not how much sleep you manage to get.

Health Effects of Working Shift Work

1. Cancer In Women

Numerous studies have now linked shift work to breast cancer in women due to high levels of reproductive hormonse and low levels of melatonin. (1)(2)

This cancer risk extends to other types of hormone related cancers in women such as ovarian and uterine cancers

A study confirmed a positive association between night shifts and the risks of several common cancers in women. This positive association increased, with the accumulating years of night shift work. So the effect is cumulative. (3)


2. Cardiovascular Disease

The effects of shift work on the heart is also well-established. Studies have been done on men and women and the relationship with coronary artery disease and shift work was confirmed. (4)

Similarly, shift work has been linked to stroke and heart disease in both men and women. (5)

3. Digestive or Gastrointestinal Disorders

Shift work has been linked to different types of digestive issues that include diarrhea, abdominal pain and constipation. A study of female nurses working night shift, especially rotating shifts, confirmed the relationship with night shift and irritable bowl syndrome and abdominal pain. (6)

4. Reduced alertness and accidents

Due to being very tired, very stressed and having hormonal imbalances, studies have shown that people who work night shifts are more likely to:

a. Have work related injuries on one-self and making mistakes that can cause injury to someone else.

b. Have more driving-related accidents. In fact, people who have had such accidents described themselves as feeling “drunk”.

c. Have more injuries during their leisure time/activities.


5. Obesity & Diabetes

Many studies have shown the clear connection between night shift workers and the risk of obesity and diabetes. This is because the hormonal imbalances trigger hunger and excessive eating. Being fatigued and stress also leads to making unhealthy eating choices such as foods high in sugar to ease the emotional stress and to give some quick energy when tired. (7)

6. Infertility

Of course we immediately think of women fertility but in fact, sleep disturbances affect both men and women’s ability to conceive.

The first study ever conducted on men in 2013, showed that there was a link between disturbed sleep patterns due to shift work, with the quality of semen. (8)

The same is true with women which makes complete sense. We have discussed in great detail, that the hormone (endocrine) system  plays a crucial role in our health, including our menstrual cycle. So anything that affects our hormones will affect our cycle which in turn will affect the likelihood of pregnancy.

A Harvard study showed that female night shift workers had fewer overall egg count, a reduction in the number of eggs ready for fertilization. This was also true for women who worked physically demanding jobs. (9)

7. Mental Health (10)

Statistics and studies regarding mental health are very concerning for women as there is a big difference in the chances of developing mental health issues such as depression and anxiety.

Overall, studies that included both men and women together, there was a 30 percent higher chance in developing mental health issues working shift work compared to the normal population. But for women alone, there is a 78% higher risk making them very vulnerable.

3How to Minimize The Effects



We can never fully battle the negative effects of night shifts or rotational shifts. Some health issues discussed are short-term, and therefore if you are lucky enough to only work shift work for a short period. Another option would be able to see if you can change and/or rotate night shifts with your work colleagues, every few months, to allow your body to recover and give your body its normal sleep-wake cycle again. This can help minimize or reverse the long term effects of shift work.

If however, you will be working shift work for many years, you need to do the most you can to minimize the effects and take preventative actions where possible.

Some of these actions you can take are:

1. Meal preparation

Being a night shift worker requires extra planning and discipline when it comes to eating habits. Meal preparation is crucial because there are limited options for finding food during the night, so it is very common to go to a fast food restaurant.

2. Education and Early Signs

Know yourself and your body and learn how to detect early signs of health issues, especially those related to heart problems and anxiety.

A suggestion is to visit your doctor more often than once a year for a check-up, even though you may “feel” fine. Ask you doctor to support you with taking more than one blood test per year to measure your hormone levels and to ensure that your blood pressure and blood sugar levels are still within normal range.

3. Mental Health

It is recommended to have a regular counselor or psychologist, when you work night shifts, especially when the job is highly stressful. The key is not to wait until you start to really have mental health issues because everyone’s baseline is different.

By identifying and meeting regularly with your psychologist BEFORE having any mental health issues, he/she can have the opportunity to assess you when you are balanced and at your “normal”.

This will allow the psychologist to be able to detect any slight deviations  from YOUR “normal” self, so that you can effectively intervene before things get worse.

Also, finding time to exercise, get outside during daytime hours and spend time with family and friends can help with mood and feeling socially isolated.


4. Sleep

As discussed, even getting normal amounts of sleep will never battle effects of shift work on the circadian rhythm. Even though this is the case we still need to maximize the quality and quantity of sleep. Why?

This will prevent you from getting in the “negative” or having what is called a sleep “debt”. Studies have shown that you can not compensate for “sleep debt” by just adding on more hours of sleep the next day or the next week. Your sleep-wake cycle is based on a 24-hour clock so you can’t make up for lost sleep days later.

To maximize your sleep, make sure you:

– Are not dehydrated and hungry before going to bed;

– Do not eat high sugar or drink caffeine within the 5-6 hours before going to bed;

– Smoking before bed is also a stimulant;

– Drinking alcohol may help you fall asleep but will affect your quality of sleep.

– Get black out blinds for your room and use background noise to help camouflage the noise from daytime noises.

– Make sure you turn off cell phone and all other distractions.

I am guilty for never having payed attention to the signs I had when working shift work. Some part of me did, but I chose to ignore them or underestimate the consequences. As a result, even after 3 years of stopping shift work, I am still suffering from a complete LACK of menstruation.

It has been confirmed that in order for me to conceive, I will have to go through IVF. I would have always had difficulty conceiving due to my PCOS diagnosis, but working shift work and not learning how to better deal with my sleeping habits worsened my issue.

I need to give credit where credit is due and also to show how diet and exercise are very important. What I mean is what I did do RIGHT, was being active daily and always eating healthy. These two habit of mine were my saving grace.

In fact, most people with PCOS develop diabetes and obesity so this coupled with night shifts should have sent me down this path. But I have no signs of insulin resistance and/or high blood sugar even until today, which shows how exercise and eating play a huge role in health, even when your body’s circadian cycle and hormonal system is obviously imbalanced and being challenged.

In the 9 years of doing shift work, I remember it clearly that only once, did I join my colleagues and ordered unhealthy meal at 2 am, because I did not bring my own dinner. I remember this night so well because it only happened once and my colleges took a photo of me eating my meal!

I hope you enjoyed reading this article and for us women, we are extra vulnerable because of  hormone-related cancers and depression.

Any of you do shift work? How many years has it been? And how do you cope?

Send me your comments and personal experience in this area!

4 thoughts on “Effects of Shift Work On The Body – Is It Manageable?”

  1. Another Excellent article, I can relate shift work …kind of. I worked in the concrete industry and our hours changed almost daily. anywhere from 3 – 6 am starts and we would finish at all different hours of the day and night. This is hard on the body and not ideal. I sit here now with 3 spine prolapses and not able to return to heavy labor. I wish I knew then what I know now about the body. RESPECT YOUR BODY. lol. I learned this the hard way.

    This is the second article from your website I have read, and I am so impressed with them. Packed with priceless information, and in easy to read paragraphs. visually exciting and interesting. Keep up the great work.

    • Wow Luke! Thank you so much for such wonderful feedback. Thank you for not only reading this post but other blogs on my site. 

      I am so sorry to hear that you are suffereing long term consequences because of your previous job. I hear you lol our body does talk to us be we are stubborn and do not always listen. I really hope you are not in physical pain due to your injuries and that you have found work that can provide satisfaction.

      I sincerely, really appreciate your comments regarding my site. I have not been up and running for long so all the feedback will be taken very seriously, so I can adjust accordingly. 

      Thank you as well for sharing your personal experience with me Luke.

  2. Hello there, thank you so much for this post, I must commend that this blog is really helpful and the style of writing here is very simple to understand but highly educational, I just got an offer to start a shift job immediately after the whole  pandemic, and I hope to appky the prinvioles I have learned here’s so I don’t get to breakdown like every one else. 

    • Thank you Jomata for coming to my site and reading some of my articles. I also really appreciate the feedback as it has not been long that my site is up and running and I want to adapt to me readers comments. I am glad my writing style is simple to understand. I want to ensure that my posts are really serving to educate people and also guiding them in the right direction to better their health.

      Yes if you will start to work shift work, you will have to make a conscious effort to really take care of yourself. I am glad you read my article and it shows you are taking the necessary steps to educate yourself before embarking on this new job.

      Good luck to you. 


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