Fig. 1
From: Fatigue in chronic inflammation - a link to pain pathways
Model of interactions between fatigue, pain and psychological disturbance. (a) Conceptual model of clinical interactions between fatigue, pain and psychological disturbance in inflammatory arthritis. (b) Conceptual model of physiological interactions between fatigue, pain and psychological disturbance in inflammatory rheumatism. The potential mechanisms of action in each domain are listed. The increase of inflammatory cytokine levels could be involved in fatigue, pain and mood disorders. HPA, hypothalamic-pituitary-adrenal; IFN, interferon; IL, interleukin; TNF, tumor necrosis factor