Research

Hormonal

Psychological stress activates the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system, leading to hyperarousal, elevated cortisol, and sleep-onset insomnia.

If you are stressed, your body is physically in 'wake mode' due to hormones like cortisol. You cannot simply 'relax' your way to sleep if the physiological stress response is active. Managing stress requires addressing the physiological arousal, not just the thoughts.

GoodSupportsHIGH confidence
Stress activates the sympatho-adreno-medullary (SAM) and HPA systems, influencing cardiovascular, catecholamine, cortisol, ACTH, and CRH hyperactivity... Excessive secretion of cortisol negatively affects neural structures... and, especially, negatively influences sleep by affecting the activity of the SAM and HPA systems.
Kuem Sun Han et al. · Experimental Neurobiology · 2012

Why this rating

The paper is a comprehensive review citing numerous primary studies, though it does not present new primary data itself.

Source

Stress and Sleep Disorder

Kuem Sun Han et al. · Experimental Neurobiology · 2012

DOI 10.5607/en.2012.21.4.141

narrative_reviewCited 307×
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DOI resolved against Crossref · corpus check 2026-06-10

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