Pain Sensitivity, Daily Rhythms, Metabolism and Pain in Youth

Fillingim's work shows that healthy people respond very differently to the same noxious stimulus, so pain response is individual and partly contextual. About 30 percent of the general population has sensory processing sensitivity, likely more in clinical practice, with genetic, environmental, emotional and hormonal links. Emotional reactivity has been tied to metabolic dysfunction, and insulin resistance appears in depression and anxiety disorders. Hormone levels shift across the 24-hour cycle. Circadian disruption is linked to maladaptive pain, and daily changes in progesterone and testosterone to fibromyalgia severity. Rolf places these fluctuations within nociceptive, nociplastic and neuropathic pain. Metabolic disorders such as diabetes, high cholesterol, thyroid disease and obesity are linked to tendon injury and Achilles rupture, and he lists visible markers such as skin tags, neck discoloration, body shape and waist circumference. Studies of children and adolescents, many from Denmark, show that daily and recurrent pain is common, often non-traumatic, and linked to female sex, high sports participation, bullying, lower family socioeconomic status and higher body mass index.