Stress

The body's stress response is mediated by the sympathetic nervous system and the hypothalmic-pituitary-adrenal (HPA) axis.

The fight-or-flight response is regulated by the release of adrenaline or noradrenaline.

Resistance is the second stage of the general adaptation syndrome, where the body has an increased capacity to respond to the stressor.

Exhaustion is the depletion and inability to maintain normal function and often results in physical illness.

Over-activation of the stress response can result in pathology and disease.