ABSTRACT
The feeling of fatigue is a universal phenomenon. For most of us it is a regular experience, a normal response of the body to physical or mental strains that may even be evaluated as pleasant. However, fatigue can also become a major complaint in a variety of physical and psychiatric illnesses such as multiple sclerosis (MS), rheumatoid arthritis, AIDS, cancer, cardial disorder, Parkinson, systemic lupus erythematosus (SLE), depression, and muscular diseases. Furthermore, fatigue can result from medical treatment as a side-effect. Complaints of fatigue directly relate to the quality of life and functional impairment in patients, but it also is a financial and economic problem for society, since fatigued employees have a decreased productivity and an increased usage of medical services (Chen, 1986; David et al., 1990). As figures on the prevalence of fatigue in the general population and in primary care vary between 10% and 25%, depending on the setting and the way it is measured, it obviously is a prominent problem that should not be underestimated (David et al., 1990; Fukuda et al., 1994).
