The ongoing stress response causes the hypothalamic-pituitary-adrenal axis in the brain to activate along highly specific pathways.
The hypothalamic-pituitary-adrenal axis (the HPA axis) refers to a complex set of direct influences and feedback interactions between the tissues within the brain (hypothalamus, pituitary gland) and the adrenal. It is the mechanism for a set of interactions among glands, hormones and parts of the mid-brain that mediate a general adaptation syndrome. The HPA systems trigger the production and release of steroid hormones including the primary stress hormone cortisol from the adrenal gland and is involved in the neurobiology of mood disorders, anxiety, bipolar disorder, post-traumatic stress, clinical depression, burnout, chronic fatigue syndrome and irritable bowel syndrome to name but a few.
Cortisol- in small amounts- is an essential hormone. In small amounts it offers positive effects such as quick bursts of energy, greater memory function, short term increased immunity, lower sensitivity to pain and it helps maintain homeostasis in the body alongside the HPA axis. It’s very important in monitoring the systems throughout the body (heart, lungs, circulation, metabolism, immune systems, skin etc) in our everyday activities that deal immediately with the stressor. It’s one of the hormones associated with waking and sleeping and its levels naturally fluctuate during the day being at its highest in the morning and lowest at night. It’s the highest levels of cortisol in the morning that help the body wake up at the start of the day.
While cortisol is an important and helpful part of the body’s response to stress, it’s important that the body’s relaxation response is activated after the removal (or perceived removal) of the stress (or stressor) so the body’s functions can return to normal. If the body’s stress response is activated so often and doesn’t return to normal, excessive levels of cortisol induce a reverse of its characteristics.
Excessive levels of cortisol changes its characteristics from one of anabolism (building) to one of more catabolism (breaking down) thereby producing negative responses opposed to positive. Physiologically these include:
To keep cortisol levels healthy and under control, the body’s relaxation response should be activated after the fight or flight response occurs. By having the body relax, making lifestyle changes and the cessation of causal factors in order to keep the body from reacting to stress, the following have been found by many to be helpful in relaxing the body and mind: