Impacts of shift work on sleep and circadian rhythms

Pathol Biol (Paris). 2014 Oct;62(5):292-301. doi: 10.1016/j.patbio.2014.08.001. Epub 2014 Sep 20.


Shift work comprises work schedules that extend beyond the typical "nine-to-five" workday, wherein schedules often comprise early work start, compressed work weeks with 12-hour shifts, and night work. According to recent American and European surveys, between 15 and 30% of adult workers are engaged in some type of shift work, with 19% of the European population reportedly working at least 2 hours between 22:00 and 05:00. The 2005 International Classification of Sleep Disorders estimates that a shift work sleep disorder can be found in 2-5% of workers. This disorder is characterized by excessive sleepiness and/or sleep disruption for at least one month in relation with the atypical work schedule. Individual tolerance to shift work remains a complex problem that is affected by the number of consecutive work hours and shifts, the rest periods, and the predictability of work schedules. Sleepiness usually occurs during night shifts and is maximal at the end of the night. Impaired vigilance and performance occur around times of increased sleepiness and can seriously compromise workers' health and safety. Indeed, workers suffering from a shift work sleep-wake disorder can fall asleep involuntarily at work or while driving back home after a night shift. Working on atypical shifts has important socioeconomic impacts as it leads to an increased risk of accidents, workers' impairment and danger to public safety, especially at night. The aim of the present review is to review the circadian and sleep-wake disturbances associated with shift work as well as their medical impacts.

Keywords: Accidents; Circadian rhythms; Contre-mesures; Countermeasures; Night shift work; Performance; Privation de sommeil; Restriction de sommeil; Rythmes circadiens; Shift work; Sleep deprivation; Sleep restriction; Travail de nuit; Travail posté.

Publication types

  • Review

MeSH terms

  • Accidents
  • Arousal / physiology
  • Automobile Driving
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / etiology
  • Circadian Rhythm / genetics
  • Circadian Rhythm / physiology*
  • Circadian Rhythm / radiation effects
  • Circadian Rhythm Signaling Peptides and Proteins / genetics
  • Circadian Rhythm Signaling Peptides and Proteins / physiology
  • Disease Susceptibility
  • Disorders of Excessive Somnolence / epidemiology
  • Disorders of Excessive Somnolence / etiology
  • Fatigue / etiology
  • Genetic Variation
  • Humans
  • Hydrocortisone / metabolism
  • Light
  • Melatonin / physiology
  • Melatonin / therapeutic use
  • Metabolic Syndrome / epidemiology
  • Metabolic Syndrome / etiology
  • Neoplasms / epidemiology
  • Neoplasms / etiology
  • Psychomotor Performance
  • Risk
  • Secretory Rate
  • Sleep Deprivation / etiology
  • Sleep Deprivation / physiopathology
  • Sleep Disorders, Circadian Rhythm / drug therapy
  • Sleep Disorders, Circadian Rhythm / epidemiology
  • Sleep Disorders, Circadian Rhythm / etiology*
  • Sleep Disorders, Circadian Rhythm / physiopathology
  • Work Schedule Tolerance / physiology*


  • Circadian Rhythm Signaling Peptides and Proteins
  • Melatonin
  • Hydrocortisone