ABSTRACT
Stress is one’s immediate physical response to environmental pressures. The stress response entails reactions of the nervous system, such as when the brain releases certain neurotransmitters; the hormonal system, which releases stress hormones; and the immune system, in which some parts go on hold so that energy can be diverted for self-protection from the stressor. Imagine a forager, quietly digging up tubers, inadvertently disturbing a rattlesnake. If the forager can act faster than normal in an effort to escape danger—which is what happens if the stress response triggers flight—the forager gains an adaptive advantage. Chronic stress also seems to tax the brain. It may even do so in a sinister way that perpetuates cycles of poverty. New science regarding the allostatic mechanisms by which stress does its damage is both fascinating and groundbreaking. However, the link between stress and ill health has long been known.
