Fatigue

Fatigue is the physical and/or mental exhaustion that can be triggered by stress, medication, overwork or mental and physical illness or disease (Ford-Martin, 2011).

In the broadest of senses, fatigue, especially at work, has been connected to an imbalance between the intensity, length, and timing of work, with recovery time.  This imbalance is frequently related to working for prolonged periods and the subsequent inability to sustain the required level of performance on a task (Dinges, 1995).