The stress response is a natural physiological response which we all experience. Originally, its purpose was to help us detect threats in our environment. Examples, wild animals, which could potentially kills us. While this is no longer the case, the stress response is still necessary and useful. It alerts us about potential threats.
When we encounter an actual threat (someone with a gun) or imagine a perceived threat (losing our employment), this sets off the stress response, or what is better known as the Flight or fight response. Our hypothalamus, a tiny structure at the base of our brain, sets off our body’s natural alarm system. Messages are sent to our adrenal glands, located on the top of our kidneys, to release a surge of hormones, primarily adrenaline and cortisol.
The main symptom we notice when we experience this Adrenaline rush is increases in heart rate. Adrenaline also elevates our blood pressure. It boosts energy supplies (more blood pumping means more oxygen in the event that we need to run). Cortisol, the primary stress hormone, increases sugars (glucose) in our bloodstream. It enhances our brain’s use of glucose (more glucose means more energy to burn in the event that we need to fight or run). Increasing the availability of substances that repair tissues. Basically, our body is preparing us either defend ourselves, or run away.
Cortisol is also responsible for controlling bodily functions that would be unnecessary or detrimental in a fight-or-flight situation. For example, it increases our immune system responses and suppresses the digestive system processes. Once a perceived threat has passed, hormone levels return to normal. As adrenaline and cortisol levels drop, our heart rate and blood pressure return to baseline levels. Other systems resume their regular activities.
If we are consistently exposed to threats, actual or perceived, it is possible for our baseline stress levels to stay stuck at high levels which would make it easier to develop anxiety disorders, as well as depression.