Shift Work Disorder is a sleeping disorder commonly affecting people who work outside normal hours (8 a.m.-6 p.m.). For those who have experienced working outside normal hours, you are likely acquainted with the negative health effects of Shift Work Disorder. Affecting approximately 15-30% of the US and European workforce, it is a disorder that is underrecognized, especially in the healthcare field.[i] Some studies indicate that about 20-30% of workers have recurrent insomnia symptoms.[ii] From my own personal experience, I never had one discussion on Shift Work Disorder or the effects of poor sleep in my training or jobs as a physician afterwards.
Unfortunately, the prevalence of Shift Work Disorder is not decreasing. With more and more of the workforce working remote, many people are having to adjust to different time zones, causing deleterious consequences on their sleep.[iii]
For those who suffer from Shift Work Disorder, even if they are trying to get their normal hours of sleep, their sleep quality may be compromised.[iv] While there are some different theories, the reason is obvious—you are constantly trying to trick your body into sleeping when it should be awake and vice versa. More than sleep quality, shift work affects performance on the job.[v] In healthcare related fields, this can affect patient care. Unfortunately, in other work areas like the industrial sector, this can cause increased mortality due to workplace accidents. Even off the jobsite, Shift Work Disorder is dangerous because it can cause accidents while driving to and from the workplace. Personally, I know two people who were involved in accidents while driving in the morning from their night shift.
How is Shift Work Disorder diagnosed?
One of the main diagnostic criteria for examining Shift Work Disorder is found in the International Classification of Sleep Disorders.[vi] The main criteria is is insomnia or excessive sleepiness that is tied with a work cycle during normal sleeping hours.[vii] In addition, the symptoms usually last for at least 3 months and are associated with changes in shift work schedules. Other criteria also exist and can usually a physician can help diagnose this condition, but usually individuals are aware they have some disorder when it is related to when they work and it is not accounted for any other environmental factor.
What are the health effects?
There is a saying in healthcare that most accidents occur at night, and it is supported by research. There is a definite relationship between shift work and accidents with one study showing that accidents are 60% higher during evening and night hours.[viii] Unfortunately, beyond making the workplace less safe, on your own body it increases your risk of coronary heart disease, stroke, cancer, diabetes, and erectile dysfunction.[ix][x][xi] Other studies show that Shift Work Disorder increases your risk of decreased bone mineral density (osteoporosis) and fracture.[xii] Shift Work Disorder may also increase your risk of dementia by not filtering out the chemicals that can cause Alzheimers.
Your diet may also change with working the swing or night shift.[xiii] You may have less fruit and vegetables, eat more snacks, eat irregularly, and eat more. The data is mixed but some believe alcohol may increase if you work different shifts.[xiv] This can unfortunately cause weight gain and is a factor with increased obesity.[xv]
Some risk factors could make Shift Work Disorder worse.[xvi] Some people lack a flexibility in their circadian rhythm that can make them able to sleep whenever. In addition, being married or having children, increased caffeine intake, differences in personality (higher neuroticism scores) also make Shift Work Disorder worse. Interestingly enough, physical activity is a protective factor.
What can I do about it?
There are many ways to combat Shift Work Disorder. However, there really is no perfect treatment. That being said, many treatments aim to trick the body into believing it is night or day. Melatonin, a hormone produced by the pineal gland, is usually suppressed with excessive light exposure. This is typically why it is recommended to not watch TV or scroll on your phone before bed. However, in shift work disorder, using melatonin after a shift has been helpful in restoring normal circadian rhythm with those on different work shifts.[xvii] While this may be difficult in many environments, some recommend having less than than 3 consecutive night shifts with breaks greater than 11 hours.[xviii] In addition, pregnant workers should not have more than one night shift at a time to reduce the risk of miscarriage. Interestingly enough, some of these recommendations were also used for the aim of preventing breast cancer.
Instead of trying to take medications that promote sleep or have a schedule conducive to better sleep, other treatment modalities such as caffeine focus on keeping you awake. Caffeine can help with giving people the energy they need to stay up late, but it comes at a cost. Unfortunately, caffeine is less effective every consecutive night you take it, and you can get withdrawal. As stated before, caffeine can also exacerbate Shift Work Disorder. So, caffeine can help, but in moderation.
Light therapy can be helpful with individuals suffering from Shift Work Disorder.[xix] This can be helpful by causing a circadian delay and allowing you to feel awake without your body producing hormones to cause sleepiness.
Taking naps during breaks can also be a helpful treatment. However, the same rules for nighttime napping also apply to daytime napping, being that taking short naps (10-30 minutes) may be more effective than longer naps (>30 minutes).[xx]
One last treatment for Shift Work Disorder is to get a new job. This is usually not feasible. However, one study showed increased burnout amongst nurses who were regularly exposed to shift work and working nights.[xxi] If you are one of those individuals who has circadian inflexibility, it may be worth considering your health over your current job and trying to find other jobs that are in alignment with your sleep cycle.If you are concerned that you have Shift Work Disorder, it is always helpful to see a doctor who specializes in sleep medicine. You may have other conditions that could be making your adjustment to the night shift better or worse
[i] Booker LA, Magee M, Rajaratnam SMW, Sletten TL, Howard ME. Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review. Sleep Med Rev. 2018 Oct;41:220-233. doi: 10.1016/j.smrv.2018.03.005. Epub 2018 Mar 27. PMID: 29680177.
[ii] Booker LA, Magee M, Rajaratnam SMW, Sletten TL, Howard ME. Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review. Sleep Med Rev. 2018 Oct;41:220-233. doi: 10.1016/j.smrv.2018.03.005. Epub 2018 Mar 27. PMID: 29680177.
[iii] Cheng P, Drake C. Shift Work Disorder. Neurol Clin. 2019 Aug;37(3):563-577. doi: 10.1016/j.ncl.2019.03.003. Epub 2019 May 7. PMID: 31256790.
[iv] McDowall K, Murphy E, Anderson K. The impact of shift work on sleep quality among nurses. Occup Med (Lond). 2017 Dec 2;67(8):621-625. doi: 10.1093/occmed/kqx152. PMID: 29040745.
[v] Ganesan S, Magee M, Stone JE, Mulhall MD, Collins A, Howard ME, Lockley SW, Rajaratnam SMW, Sletten TL. The Impact of Shift Work on Sleep, Alertness and Performance in Healthcare Workers. Sci Rep. 2019 Mar 15;9(1):4635. doi: 10.1038/s41598-019-40914-x. PMID: 30874565; PMCID: PMC6420632.
[vi] Wickwire EM, Geiger-Brown J, Scharf SM, Drake CL. Shift Work and Shift Work Sleep Disorder: Clinical and Organizational Perspectives. Chest. 2017 May;151(5):1156-1172. doi: 10.1016/j.chest.2016.12.007. Epub 2016 Dec 21. PMID: 28012806; PMCID: PMC6859247.
[vii] Drake CL, Roehrs T, Richardson G, Walsh JK, Roth T. Shift work sleep disorder: prevalence and consequences beyond that of symptomatic day workers. Sleep. 2004 Dec 15;27(8):1453-62. doi: 10.1093/sleep/27.8.1453. PMID: 15683134.
[viii] Wickwire EM, Geiger-Brown J, Scharf SM, Drake CL. Shift Work and Shift Work Sleep Disorder: Clinical and Organizational Perspectives. Chest. 2017 May;151(5):1156-1172. doi: 10.1016/j.chest.2016.12.007. Epub 2016 Dec 21. PMID: 28012806; PMCID: PMC6859247.
[ix] Kecklund G, Axelsson J. Health consequences of shift work and insufficient sleep. BMJ. 2016 Nov 1;355:i5210. doi: 10.1136/bmj.i5210. PMID: 27803010.
[x] Ulhôa MA, Marqueze EC, Burgos LG, Moreno CR. Shift work and endocrine disorders. Int J Endocrinol. 2015;2015:826249. doi: 10.1155/2015/826249. Epub 2015 Mar 29. PMID: 25892993; PMCID: PMC4393906.
[xi] Rodriguez KM, Kohn TP, Kohn JR, Sigalos JT, Kirby EW, Pickett SM, Pastuszak AW, Lipshultz LI. Shift Work Sleep Disorder and Night Shift Work Significantly Impair Erectile Function. J Sex Med. 2020 Sep;17(9):1687-1693. doi: 10.1016/j.jsxm.2020.06.009. Epub 2020 Jul 28. PMID: 32736945; PMCID: PMC7484090.
[xii] Feskanich D, Hankinson SE, Schernhammer ES. Nightshift work and fracture risk: the Nurses' Health Study. Osteoporos Int. 2009 Apr;20(4):537-42. doi: 10.1007/s00198-008-0729-5. Epub 2008 Sep 3. PMID: 18766292; PMCID: PMC2651998.
[xiii] Pepłońska B, Nowak P, Trafalska E. The association between night shift work and nutrition patterns among nurses: a literature review. Med Pr. 2019 Jun 14;70(3):363-376. doi: 10.13075/mp.5893.00816. Epub 2019 May 14. PMID: 31086356.
[xiv] Skovenborg E. Shift work and diabetes: alcohol consumption as a risk factor. BMJ. 2019 Jan 16;364:l177. doi: 10.1136/bmj.l177. PMID: 30651233.
[xv] Brum MCB, Dantas Filho FF, Schnorr CC, Bertoletti OA, Bottega GB, da Costa Rodrigues T. Night shift work, short sleep and obesity. Diabetol Metab Syndr. 2020 Feb 10;12:13. doi: 10.1186/s13098-020-0524-9. PMID: 32064002; PMCID: PMC7011518.
[xvi] Booker LA, Magee M, Rajaratnam SMW, Sletten TL, Howard ME. Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review. Sleep Med Rev. 2018 Oct;41:220-233. doi: 10.1016/j.smrv.2018.03.005. Epub 2018 Mar 27. PMID: 29680177.
[xvii] Sack RL, Lewy AJ. Melatonin as a chronobiotic: treatment of circadian desynchrony in night workers and the blind. J Biol Rhythms. 1997 Dec;12(6):595-603. doi: 10.1177/074873049701200615. PMID: 9406035.
[xviii] Garde AH, Begtrup L, Bjorvatn B, Bonde JP, Hansen J, Hansen ÅM, Härmä M, Jensen MA, Kecklund G, Kolstad HA, Larsen AD, Lie JA, Moreno CR, Nabe-Nielsen K, Sallinen M. How to schedule night shift work in order to reduce health and safety risks. Scand J Work Environ Health. 2020 Nov 1;46(6):557-569. doi: 10.5271/sjweh.3920. Epub 2020 Sep 8. PMID: 32895725; PMCID: PMC7737811.
[xix] Gumenyuk V, Roth T, Drake CL. Circadian phase, sleepiness, and light exposure assessment in night workers with and without shift work disorder. Chronobiol Int. 2012 Aug;29(7):928-36. doi: 10.3109/07420528.2012.699356. PMID: 22823876.
[xx] Kolla BP, Auger RR. Jet lag and shift work sleep disorders: how to help reset the internal clock. Cleve Clin J Med. 2011 Oct;78(10):675-84. doi: 10.3949/ccjm.78a.10083. PMID: 21968474.
[xxi] Giorgi F, Mattei A, Notarnicola I, Petrucci C, Lancia L. Can sleep quality and burnout affect the job performance of shift-work nurses? A hospital cross-sectional study. J Adv Nurs. 2018 Mar;74(3):698-708. doi: 10.1111/jan.13484. Epub 2017 Nov 22. PMID: 29164664.