Figure 1.

Visual representation of the major stress pathways, together with common dysregulations in chronic pain and their possible pathophysiological implications in stress intolerance. ↑, Increased; ↓, Decreased; ACh, Acetylcholine; Adr, Adrenaline; ACTH, Adrenocorticotropic hormone; COMT, Catechol-O-methyltransferase; CNS, Central nervous system; CWP, Chronic widespread pain; CRH, Corticotropin-releasing hormone; mDNA, DNA methylation; GR, Glucocorticoid receptor; HRV, Heart rate variability; HPA axis, Hypothalamic-pituitary-adrenal axis; MAO-A&B, Monoamine oxidase A&B; NA, Noradrenaline. Created with BioRender.com (Accessed on 9 February 2023).