Fatigue is one of the most common symptoms patients cite to their health care providers. The source of the problem stems from all parts of the body including the nervous system, musculoskeletal system and endocrine. Newer conceptions of fatigue identify significant contributions from substances produced by the central nervous system. Lynn Gerber, professor and director for the Center for Study of Chronic Illness and Disability at George Mason University, examines the complexities of fatigue and how we can ameliorate its effects. From the Series:The Vision Series