Fatigue is a state of feeling tired and weak resulting from prolonged mental or physical work or stress. It can be acute from short-term causes or chronic from long-lasting issues. Fatigue affects physical and mental functioning and can impact work performance, relationships, and daily activities. Work-related factors like long hours and stress as well as sleep disorders are common causes of fatigue. Employers can help reduce fatigue by providing good lighting, comfortable temperatures, limiting noise, varying tasks, and accommodations for employees working extended hours.