What exactly is the hormonal stress theory?

Stress theory: Hormonal stress theory is a theory that attributes stress responses to stressors (internal or external stimuli) that cause a cascade of hormonal reactions involving multiple hormones, especially the hypothalamic, pituitary, adrenal axis involving crh, acth, cortisol, and eventually norepinephrine and serotonin as well as peptide y which is involved in resilience.