Fatigue and Sleepiness

Fatigue and sleepiness can be debilitating conditions, resulting in impaired functioning and quality of life. The two distinct constructs may have different but overlapping causes, including medical conditions or underlying sleep disorders. With the exception of chronic fatigue syndrome (CFS), fatigue is conceptualized as a symptom rather than a disorder. Fatigue is a subjective sense of low energy and/or exhaustion. Treatment of fatigue typically focuses on addressing underlying conditions likely causing the fatigue. Sleepiness can be either a subjective state of feeling the desire to sleep or an objective state of the inability to maintain wakefulness. In some cases, this may be diagnosed as a sleep disorder; however, it is more commonly the result of inadequate nighttime sleep. As a result, sleepiness is typically addressed by improving the quality and/or quantity of nighttime sleep. In some cases, disorders of excessive daytime sleepiness, such as in the case of narcolepsy, require direct pharmacological therapy.