Fig. 1.

Fatigue as a multidimensional concept implemented in the World Health Organization’s Classification of Functioning, Disability, and Health. The multidimensional concept of fatigue is integrated in the World Health Organization’s International Classification of Functioning, Disability and Health (WHO-ICF), representing the effect of disease on body function and structure, activity and participation of the patient [1]. Both experienced fatigue and physiological fatigue have an effect on activity and participation and are in most diseases related to health status and disease severity. Psychosocial factors have an influence on fatigue and on activity and participation. The numbers indicate at which level the different treatment strategies have an effect on fatigue: I treatment of underlying disease; II rehabilitation and exercise; III pharmacotherapeutics; IV cognitive behavior therapy