Inflammation at the Intersection of Behavior and Somatic Symptoms

Pain, sleep disturbance, and fatigue are common complaints in somatic disorders. This review characterizes the connections between the immune system and brain, discussing the influence of proinflammatory cytokines on somatic symptoms of pain or hyperalgesia, sleep disturbance, and fatigue. It is hypothesized that increases of peripheral inflammation markers, possibly acting in concert with stress, leads to activation of central inflammatory pathways with increased sensitization of the central nervous system to afferent signaling. These psychoneuroimmunologic pathways contribute to symptoms of pain and fatigue, and/or amplification of normal bodily sensations, which lead to distress and impairments in social, occupational, and health functioning.