Although similar, postoperative pain and the surgical stress response are not the same. Surgical stress causes release of cytokines and precipitates adverse neuroendocrine and sympathoadrenal responses (increased secretion of the catabolic hormones [cortisol, glucagon, growth hormone, and catecholamines] and decreased secretion of the anabolic hormones [insulin and testosterone]) (Table 56-3: Consequences of Poorly Managed Acute Pain).