March 11th, 2010
03:27 PM ET

Is working the night shift unhealthy?

According to a 2004 survey by the U.S. Bureau of Labor Statistics, a little more than 3 percent of full-time wage and salary workers work night shifts - defined as shifts between the hours of 9 p.m. and 8 a.m.  Another 2.5 percent work rotating shifts, which can include overnight shifts.

The Cleveland Clinic in Cleveland, Ohio, reports that overnight workers suffer from a condition called Shift Work Sleep Disorder, with symptoms including insomnia, excessive sleepiness, difficulty concentrating and lack of energy. Lately, there have been some studies suggesting that overnight work can have more serious health effects.

Fact Check: Is working overnight hazardous to your health?

- The Fred Hutchinson Cancer Research Center in Seattle, Washington, conducted a 2001 study that compared 800 Seattle-area women who had been diagnosed with breast cancer to 800 women who had not been diagnosed with breast cancer. Researchers concluded that women who had worked the overnight shift had a 60 percent increased risk for breast cancer. In addition, they said, "The risk of breast cancer increased with each additional hour per week of graveyard-shift work." Despite those findings, the author of the report cautioned, "It is too early to say that (working at night) 'causes' breast
cancer."

- A 2001 study by Boston, Massachusetts' Brigham and Women's Hospital of 78,562 nurses noted "a moderate increase in breast cancer risk among the women who worked 1-14 years or 15-29 years on rotating night shifts. The risk was further increased among women who worked 30 or more years on the night shift."

- In 2008, the Danish government recognized breast cancer after night-shift work as an industrial injury, and granted compensation in 37 cases. According to Denmark's Occupational Diseases Committee, "the injured person typically had night-shift work for at least 20-30 years, and at least once a week."

- In 2009, Brigham and Women's Hospital studied 10 healthy volunteers over 10 days. Researchers say hormone levels "showed the largest deviations" when the volunteers were sleeping during the day and awake all night. They concluded that abnormal hormone levels "may lead to increased health problems common in shift workers." Those problems, the researchers said, include increased risks of obesity, hypertension and diabetes."

Bottom Line:

While much more research needs to be done into the health effects of night-shift work, studies suggest possible links between night shift work and serious health problems.

- CNN's Tim Langmaid contributed to this report.

Got something that needs checking? E-mail us at factcheck@cnn.com

Post by:
Filed under: Fact Check
soundoff (26 Responses)
  1. George sarpong

    Hi this vividly true because the the reason is that I personely worked overnight , i found it very dificult when i come home in the morniing, am always thinking about my old ages what my health will look like.

    March 12, 2010 at 2:40 am | Report abuse |
  2. George sarpong

    Hi this is vividly true because the reason is that I personely worked overnight , I found it very dificult when i come home in the morning ,and am alwalys thinking about my olding ages what my health will look like.

    March 12, 2010 at 3:06 am | Report abuse |
  3. Loppo

    There COULD be a correlation with night shift and various health issues, but in all honesty, I believe it is a by product of habbits formed by some night shifters. A large amount smoke, eat entirely to much during downtime, and do not get any exercise what so ever. Thus, you acquire some health problems because of behaviors, not necessarily night shift.

    March 12, 2010 at 5:21 am | Report abuse |
    • Lace

      Um, then that would still be because of the night shift. Get it?

      July 14, 2012 at 10:27 am | Report abuse |
    • Lol

      Lol Lace I totally get it. Loppo, u need to experience the night shift for at least a year then come back n make a comment please!!!

      September 25, 2013 at 1:08 am | Report abuse |
  4. George sarpong

    Hi I Just want to know if you work the whole of your life in overnight what will cause your health, I was wwondering if i will an respond answer from you. thank you

    March 12, 2010 at 6:36 am | Report abuse |
  5. Phoenix Abby

    Gee, who knew? The job I said was killing me really was killing me LOL Is there really a lawsuit out there for this? I worked nights for almost 9 years and my health declined substancially

    March 12, 2010 at 4:08 pm | Report abuse |
  6. Angelo

    I have been working the night shift for ten years and have suspected that there was some connection between health problems and working the nightshift and there it is an article talking about this.

    Behavior has nothing to do with the various health issue that was addressed in the article.

    March 12, 2010 at 11:45 pm | Report abuse |
    • night shift worker

      I have been on the midnight to 8 shift for 23 years. I go to the gym , eat right and don't make dumb excuss like most of you are. If you live a slob then you will be a slob. its not always because of the hours you work. Its just being too lazy to adjust yourself correctly and to take care of your body. I cant fathom that the Danish government actually granted a settlements for this non scense. I think a very small percent of people can actually claim that working over night is bad for your health. I think most people just want to find an excuse to get off midnights or just be lazy!

      January 7, 2013 at 2:35 pm | Report abuse |
    • Lol

      To night shift worker,
      I worked graveyard shift at a casino for about 20 year now n i just turned 40 this year. Like u, I took care of my body too by going to gym, eat healthy n sleep at much as I can etc, etc... It was hard in the beginning but then my body got used to it. However, in the past few year, I can feel my health is deteriorating internally. I went to see my doctor more often and she recommend that I should get back to 8-4 shift if possible because it's going downhill from here on. I understand each n everyone of us is difference but I can tell u that many of my co-worker ain't happy as they used to be. If whoever u are have a choice between working normal n late hour shift, pick the normal hour please because u will do your body a favor in the long run n not to mention, it's NORMAL.... Normal social life too...

      September 25, 2013 at 1:28 am | Report abuse |
  7. angel

    I personally worked during night shift and it really hard to get a nice sleep during daytime. I agree that there's really a correlation with night shift and various health issues this is because if you work during night time you tend to eat lots of foods, you drink too much of coffee and other energy drink, others smoke a lot, in short we earn habbits that are harmful to our health.

    March 13, 2010 at 10:34 am | Report abuse |
  8. loriann

    I'm a nurse and worked the majority of my career on night shift. However, I personally am a night person. I believe one of the keys to nightshift is getting enough sleep. I make my sleep environment dark, adjust my meals, my appointments around my sleep time. Sometimes not easy as the "outside" world does not take into account my sleep hours.I make doctor appts.early am or last appt of the day for instance. I take a walk when i get off work. When I had kids, this was not always possible, but did the best I could. Some people with kids get very little sleep, and some simply can't sleep daytime. I do agree it is determental to work "graveyard" but can be worked out to a degree.

    March 13, 2010 at 4:16 pm | Report abuse |
  9. blackerider

    Loppo is entirely correct in his/her assessment of poor habits being more associated with declining health than simply working the night shift. I have done the night shift for many years, and I am a marathoner, nordic skate skiier, speedskater and cyclist. I also stick to a very strict schedule of sleep discipline and dietary discipline. I am over 40 years old, and have never felt better. My colleagues and contemporaries that do not exercise discipline in their lives in the areas of diet, sleep, and activity – whether day ot night shift workers – have a whole host of problems that they talk to me about at length. Since I am in a medical profession, and people come to me for advice on these issues, I have found that over time the advice I give to people is ignored for one simple reason: people do not want to exercise discipline and self-censorship for the benefit of their ong-term health. Instead, they sacrifice it for short-term pleasure and apathy. The disciplined lessons of the previous Gretest Generation seem to have been lost on a society bent on immediate gratification instead of the only investment that really matters – your health. I have three other colleages that work the night shift that are marathoners, and several others that are active walkers, cyclists, and in-line skaters. We're all doing great:) Whether working the night shift or day shift, the importance of education regarding activity cannot be overstated: you MUST be active to maintain health. All the evidence we see in medicine makes it abundantly clear. The #1 thing you can do to improve and maintain your health is to remain active (and quit smoking if you are a smoker), regardless of what shift you work.

    March 14, 2010 at 3:36 pm | Report abuse |
    • Keamba Manning

      I am just wondering what kind of work you do exactly and what kind of hours you are working, that you have time to run marathons, ski, be a cyclist (etc.) I work overnight as a night auditor and go to school full time and I would not be able to do all of these things. Even during the summer when I am not in school. I think that is definitely something to these findings about the effects of working overnight. Since I have been working oernight I have just had a feeling that it was doing something to my health. I tend to feel tired and sleepy alot of the time. i just don't feel as alive as I did when I worked during the day. Also, you seem to be quite educated so I'm sure you know that it is a widely held belief among the scientific community that for various reasons humans have evolved to sleep at night versus the day and this belief is supported by humans apparent lack of features that would make them suitable to survive in the wild as nocturnal creatures. Therefore, it would seem that such an unnatural requirement of the human body would come with consequences, maybe even some more serious than one would deduct. I think that more research should be done in order to identify what these consequences are so that people can make educated desicions as to whether working overnight is worth it for them in the long term. In a society were people spend a vast amount of time at their jobs, I think they deserve to know whether or not its killing them. Would you not agree?

      August 25, 2010 at 5:10 am | Report abuse |
  10. Isaiah Roberts

    sleep disorders can also lead to other health issues like cardiovascular disorders~;,

    October 6, 2010 at 4:43 am | Report abuse |
  11. Mirror Tiles 

    sleep disorders should be treated as soon as possible coz it has a long term health effects~*'

    October 20, 2010 at 8:16 am | Report abuse |
  12. Shower Screen ·

    sleep disorders shoudl be given a timely solution to prevent further bad health side effects "

    November 9, 2010 at 10:47 pm | Report abuse |
  13. Ezza Five

    What about us musicians? OMG, I'm so shocked. All my life, since age 14, I've been contributing music to the world, live and recorded. Without music, what would this world BE? Of necessity I changed my body clock upside down so that I could do up to 8 gigs per week. This has gone on for 20+ years.
    And I am just now recovering from a long battle with breast cancer, which began in late 2004. I thank G-d I am even alive today. If I had known the risks, I may have chosen not to be a musician.
    People, next time you listen to your favourite music, realize what a HUGE sacrifice these artists have made to uplift and inspire your life.

    December 27, 2010 at 11:28 pm | Report abuse |
    • lobw

      Little hero complex much? An entertainer who wants people to literally praise and thank them for their "sacrifice?" That's hilarious. I think I'll thank the cops and paramedics who work overnights, thanks.

      July 14, 2012 at 10:33 am | Report abuse |
    • night shift worker

      Lol, you cant be serious. You made a sacrafice by making music. No pal, people who serve our country in the military or public safety sacrafice, get real!!

      January 7, 2013 at 2:40 pm | Report abuse |
  14. Negga-Tron 9000

    I just started working an overnight doorman job and I've already noticed a drastic change in mood, eating and smoking habits, lack of energy or desire to really do anything. I work alone and come home to sleep with my fiance and in a few hours she's up and out to work, often times waking me to see eachother for a few minutes and a lot of times I can't go back to sleep. This is ontop of wanting to do something when I get home in the morning and knowing I have to sleep but cannot. During my off-time the people in my life are working and vice-versa. The money is good and the economy sucks and isn't getting any better. I'm miserable but I keep my mouth shut and thank God I have a job to begin with but it's only a matter of time before I am defeated by this job both mentally and physically.

    June 23, 2011 at 8:00 pm | Report abuse |
    • IanHunter181

      Am now working as doorman 3-11. May have the (opportunity???) to move to overnight shift. Is it any better now?

      January 2, 2012 at 6:53 pm | Report abuse |
  15. Ravi

    Working at night is against nature . We designed to different things cuffedrent point of time . So if not for money no body would like do any thing at night but sleeping .

    July 7, 2013 at 3:56 am | Report abuse |
1 2