“…Cortisol has also been found to correlate inversely with pain intensity and number of pain sites in chronic pain patients (Morrison et al, 2000). Reduced adrenocortical activity has been documented in patients with chronic pain (Valdes et al, 1989), abdominal pain (Alfven et al, 1994), chronic pelvic pain (Heim et al, 1998), chronic headache (Elwan et al, 1991), low back pain (Theorell et al, 2000), fibromyalgia (Crofford et al, 1994; Griep et al, 1993), rheumatoid arthritis (Chikanza et al, 1992; Hedman et al, 1992), and chronic fatigue syndrome (Demitrack and Crofford, 1998; Demitrack et al, 1991). In light of these interactions between HPA hormones and pain sensitivity and the observed blunted cortisol response to stress in smokers, we propose that the blunted stress response contributed to the enhanced pain sensitivity and absence of stress-induced analgesia in smokers.…”