Stress Physiology
category
Stress physiology is the biological architecture of the threat-response system — encompassing the HPA axis (hypothalamus releasing CRH → pituitary releasing ACTH → adrenal cortex releasing cortisol), the sympatho-adrenal system (sympathetic nervous system releasing adrenaline and noradrenaline within seconds of threat perception), the inflammatory cytokine cascade (IL-1β, IL-6, TNF-alpha elevating to prepare immune defense), and the suppression of the parasympathetic 'rest-and-digest' system — collectively producing the cardiovascular, metabolic, cognitive, and immunological changes that optimize short-term survival performance while imposing long-term biological costs when chronically activated.
Role
Understanding stress physiology is the foundation of all effective stress management — because managing a system you don't understand is impossible, while understanding the precise biological mechanisms of chronic stress activation transforms it from a vague 'feeling overwhelmed' into a specific, diagnosable physiological state with measurable biomarkers and targeted interventions. Most people attempting to manage stress are working at the symptom level (reducing the subjective feeling of being stressed) without any model of the biological cascade driving those symptoms — producing interventions that are insufficiently matched to the mechanisms they need to address.
Subtopics
- HPA Axis The hypothalamic-pituitary-adrenal (HPA) axis is the primary neuroendocrine stress response system —…
- Cortisol Effects Cortisol produces comprehensive physiological effects across nearly every organ system — elevating b…
- Fight-or-Flight Response The sympatho-adrenal stress response activates within seconds of threat perception — the hypothalamu…
- Allostatic Load Allostatic load is the cumulative biological cost of chronic stress adaptation — the wear and tear o…
- Chronic vs Acute Stress Acute stress — brief, intense, with defined resolution — activates the same biological cascade as ch…
- Autonomic Balance The autonomic nervous system operates as a dynamic balance between sympathetic ('fight-or-flight,' a…
- Stress & Neuroinflammation Chronic psychological stress produces neuroinflammation — activation of microglia (the brain's immun…
- Hormetic Stress Hormesis is the biological phenomenon in which low-to-moderate doses of a stressor produce adaptive …
- Stress Epigenetics Chronic stress produces epigenetic modifications — heritable changes in gene expression without DNA …
- Stress Biomarkers Measurable biological markers of chronic stress activation include: morning salivary cortisol (the c…