Tired of pain? Toward a better understanding of fatigue in chronic pain
Fatigue is a prevalent complaint in people with chronic pain.11,46 A study in the general population showed that 64% of the individuals with chronic widespread pain reported co-occurring persistent fatigue.13 In patients with chronic pain due to spinal cord injury, 70% reported persistent fatigue.12 Such comorbid fatigue is likely to be an additional source of disability and suffering when left untreated.1,25,42 Moreover, fatigue might reduce patients' ability and/or willingness to fully engage in treatments aimed at increasing physical activity, such as graded activity or exposure,58 possibly lowering effectiveness. As such, a good understanding of fatigue in chronic pain patients is crucial. The aim of this review is to discuss the current knowledge on fatigue in chronic pain, to provide conceptual clarification of fatigue, and to develop a theoretical framework explaining fatigue in the context of chronic pain. Based on this framework we discuss a new research agenda and provide recommendations for clinical practice.