Work and Fatigue

fatigue banner of workers

Work and Fatigue

Fatigue has been described as “a feeling of weariness, tiredness or lack of energy.”In workplace settings, it is commonly associated with nonstandard schedules which disrupt or shorten sleep. Examples of nonstandard schedules include night shift work and extended work hours. Nearly 30% of the American workforce has a work schedule that is outside of a “regular daytime shift.”2 One in four workers reports working more than 40 hours per week. 3 Fatigue can also be associated with other workplace factors, such as:

  • Stress
  • Physically or mentally demanding tasks
  • Working in hot environments

It can stem from several different factors and its effects extend beyond sleepiness.

Fatigue can:

  • Slow down reaction times
  • Reduce attention or concentration
  • Limit short-term memory
  • Impair judgment

High levels of fatigue can affect any worker in any job. It has serious consequences for worker safety and health. Fatigue-related safety issues can occur every day, as tired workers drive on public roads, raising public health and safety concerns.4, 5

To keep workers safe and healthy, organizations should:

  • Learn the risks for fatigue-related events.
  • Identify the sources of fatigue.
  • Use strategies to prevent and manage fatigue.

About the Center for Work and Fatigue Research

The mission of the NIOSH Center for Work and Fatigue Research is to expand work on health and safety risks related to nonstandard schedules and other sources of fatigue. The Center works to develop practical, effective solutions to address these risks. To achieve these goals, the Center collaborates with researchers, policymakers, employers, workers, and health and safety professionals.

2021 CWFR Performance One-Pager

Contact the Center for Work and Fatigue Research


A.D.A.M. Medical Encyclopedia [Internet]. Fatigue; [reviewed 2019 Apr 16; cited 2020 Dec 12]; Available from:

2 2015 National Health Interview Survey, Occupational Health Supplement.

3 2019 Bureau of Labor Force Statistics, Current Population Survey.

4 National Safety Council. Drowsy Driving.

5 National Highway Transportation Safety Administration.