But for some people, fatigue is a daily experience that affects all parts of their lives. Rest may lessen the severity of chronic fatigue, but often it does not relieve it. Patients with chronic illnesses and those undergoing cancer treatment may need to alter their lifestyles to manage fatigue. According to North American Nursing Diagnosis Association guidelines, the major defining characteristic of chronic fatigue is the patient's self-report of a sustained and significant lack of energy. 5 Research on fatigue is focusing on fatigue-related symptoms in otherwise healthy people following viral infections and on fatigue as a side effect of cancer treatment.
Chronic fatigue occurs in many clinical situations and is a sequela of many treatment modalities.
About 70 percent of patients with CFS are female. Although researchers have proposed a number of mechanisms for CFS, the etiology remains unknown. The diagnosis is one of exclusion, and treatment is mainly supportive. Some clinicians think that CFS is a chronic viral syndrome. Others believe that it is caused by a mineral deficiency or that it is an immune system disorder, an allergic process, or a psychiatric disorder involving depression or somatization.