The Neurobiology of Stress: What Happens in Your Brain and Body

“Sometimes the most important thing in a whole day is the rest we take between two deep breaths.” – Etty Hillesum

Photo by Bhautik Patel on Unsplash

Stress, a deeply rooted response mechanism tied to survival, has evolved as a critical adaptive system enabling organisms to handle threats, preserve energy for essential processes, and maintain overall homeostasis in dynamic environments (McEwen & Wingfield, 2010). While short-term stress can mobilize crucial physiological and psychological resources, chronic or mismanaged stress exerts detrimental influences that permeate emotional well-being, cognitive function, and physical health (Lupien, McEwen, Gunnar, & Heim, 2009). From accelerating cardiovascular wear to impairing memory and immune responses, sustained stress can transform from a momentary defense into a persistent burden that shapes long-term mental and bodily outcomes (American Psychological Association [APA], 2019). Understanding the underlying biological mechanisms of stress — how it is triggered, regulated, and manifested in the brain and body — illuminates why certain coping strategies can mitigate its effects, and why chronic stress, left unaddressed, can gradually erode resilience (Dantzer & Kelley,1989; Noushad et al., 2021; Selye, 1956).

By delving into stress physiology, this article clarifies the continuum of acute to chronic…