Stress helps you meet your daily challenges and motivates you to reach your goals, ultimately making you a smarter, happier, and healthier person. However when you are stressed, what body reactions or clinical manifestations do you often experience? After studying the endocrine system and the stress response, can you explain how these clinical manifestations occur?
The type of healthy stress that pushes us out of our comfort zones and enables us to surpass our own limits is called "eustress". It is the fuel for our excitement and the headlight that allows us to see challenges as an opportunity for growth (Lindberg, 2019). On the flip side of the coin is another type of stress known as "distress". This is the stress that we commonly associate with unpleasant emotions, such as the fear of being chased by a rabid dog or the painful memories brought upon by a recent heartbreak (American Cancer Society, 2020). This negative form of stress triggers changes that affect not only the mind but also the body. Thus, to fully grasp the concept of stress, one needs to venture beyond the field of psychology and enter the realm of physiology.
Stress is a multi-step process that is best explained by the General Adaptation Syndrome model proposed by Hans Selye in 1936. It stipulates that the body's response to stress can be categorized into 3 phases: 1) alarm or fight-or-flight, 2) resistance, and 3) exhaustion. Tortora and Derrickson (2018) explain the process in great detail as follows:
The first phase called "alarm/fight-or-flight" begins when the hypothalamus signals the autonomic nervous system to prepare for physical activity. It is marked by an influx of glucose and oxygen to organs that actively fend off danger, such as the brain, the heart, and the skeletal muscles. I would describe it as that sudden spike in heart rate that can jolt anyone awake. A perfect example of this is my experience from less than an hour ago, in which my eyes were already shut tight and ready for slumber when I came to the terrifying realization that I forgot to accomplish the activity for this lesson. As a result, I am now functioning at full energy almost as though 3 cups of coffee are injected directly into my veins.
The second phase referred to as "resistance" features a cascade of various hormones that elicit a longer-lasting response. It involves a myriad of tropic hormones such as the corticotropin-releasing hormone (CRH), growth hormone-releasing hormone (GHRH), and thyrotropin-releasing hormone (TRH). The release of cortisol stimulates the production of glucose as well as the breakdown of fats and proteins to provide sources of energy for ATP production. Continuing on with my personal example earlier, this phase explains my current state of full concentration, with my fingers moving almost like they're racing against one another to type as quickly as possible.
Finally, the third phase aptly named "exhaustion" manifests through the wearing down of muscle, suppression of the immune system, and ulceration of the gastrointestinal tract. It occurs when resistance lingers for too long even after the stressor has been eliminated. Fortunately, I have not reached this phase despite being stressed with finishing this activity at the last minute. But in the moments when stress seemed to overpower me, I often get a strong, thumping sensation in my head that renders me weak and powerless. I like to interpret it as my body's way of urging me to take a break. This is precisely what I will be doing right now as I press the submit button and drift off to sleep.
REFERENCES:
American Cancer Society Medical and Editorial Content Team. (2020, February 1). What is distress? American Cancer Society. https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/emotional-mood-changes/distress/what-is-distress.html#written_by
Lindberg, S. (2019, January 3). Eustress: The good stress. Healthline. https://www.healthline.com/health/eustress
Tortora, G. J., & Derrickson, B. H. (2018). Principles of anatomy and physiology. John Wiley & Sons.