TY - CHAP M1 - Book, Section TI - FATIGUE A1 - Gelfand, Jeffrey M. A1 - Douglas, Vanja C. A2 - Hauser, Stephen L. A2 - Josephson, S. Andrew PY - 2018 T2 - Harrison's Neurology in Clinical Medicine, 4e AB - Fatigue is one of the most common symptoms in clinical medicine. It is a prominent manifestation of a number of systemic, neurologic, and psychiatric syndromes, although a precise cause will not be identified in a substantial minority of patients. Fatigue refers to an inherently subjective human experience of physical and mental weariness, sluggishness, and exhaustion. In the context of clinical medicine, fatigue is most typically and practically defined as difficulty initiating or maintaining voluntary mental or physical activity. Nearly everyone who has ever been ill with a self-limited infection has experienced this near-universal symptomatology, and fatigue is usually brought to medical attention only when it is either of unclear cause or the severity is out of proportion with what would be expected for the associated trigger. Fatigue should be distinguished from muscle weakness, a reduction of neuromuscular power (Chap. 14); most patients complaining of fatigue are not truly weak when direct muscle power is tested. By definition, fatigue is also distinct from somnolence and dyspnea on exertion, although patients may use the word fatigue to describe those two symptoms. The task facing clinicians when a patient presents with fatigue is to identify an underlying cause if one exists and to develop a therapeutic alliance, the goal of which is to spare patients expensive and fruitless diagnostic workups and steer them toward effective therapy. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - neurology.mhmedical.com/content.aspx?aid=1145767870 ER -