Stress
We all experience stress; whether mental or physical, stress activates a physiological response in the hypothalamic-pituitary-adrenal (HPA) axis, raising the level of cortisol produced by the adrenal glands.
This reflex, also known as the "fight or flight" response, is rather normal, and to some extent, healthy. However, when stress becomes overwhelming, it can result in issues like tension, depression, weight gain, and sleep disturbances.