HISTORY OF STRESS
Prior to the 1920’s, the term “stress”, as we commonly refer to it, was not in common use. Up to that point in time, the word was used to refer to the internal distribution of force exerted on a material body. It was only in the late 1920’s that the idea of “mental strain” or “stress” (as it’s commonly referred to now) become a clinical focus.
The notion of stress is predicated on the idea of homeostasis or equilibrium. Our bodies are governed by sophisticated autonomic processes that regulate a delicate internal balance. For example, if our body temperature rises more than a few degrees due to exercise, our body automatically responds by sweating perspiration to the surface of our skin to help cool us down and restore the body to our homeostatic preference of 98.6 F (37 C).
COPING vs STRESS
From the moment we wake up, we are confronted by stressors; some minor, others more taxing. When a stressor event exerts a strain that is less than the combination of our internal and external resources, we are able to cope. But when our resources are outmatched by the strain of a stressor event, we experience and have an awareness of emotional stress.
BIOLOGY OF THE STRESS RESPONSE
In response to stress, our brain activates our sympathetic nervous system which regulates key body functions making us more adaptable. Once our brain discerns a threat (e.g. stressor), the hypothalamus secretes a series of hormones to activate our natural defense system.
First, the pituitary gland gets activated to maintain a homeostatic balance of critical bodily functions. Second, the amygdala gets activated to discern any imminent threat to our body. The amygdala plays a central role in the emotion of fear. The amygdala releases a jolt of the brain chemical catecholamine to arouse and excite our bodies into hyper-alertness. The purpose is to determine if the perceived threat is real or passing.
If it turns out that the threat is empty (e.g. being scared by a playful prank), then the catecholamines will be reabsorbed and initiate a shutdown of our alert system, returning our body to its pre-threat homeostatic balance. But, if a threat is deemed legitimate, the amygdala will activate the adrenal gland to flood our blood stream with two stress hormones: adrenaline and cortisol.
The sole purpose of adrenaline is to keep us alive to see another day. When adrenaline hits our blood stream it activates our fight, flight or freeze response. Our respirations and heart rate increase, pulling in more oxygen to oxygenate our blood to be pumped to all vital organs and muscles to access our strength while muting our pain sensitivity. Next, it focuses our attention to monitor the threat. Next, it restricts our abstract thinking abilities to basic survival mental processes. Adrenaline is only meant to be activated over the short term. Once we’ve fought off the threat or made our way to safety, the adrenaline is to be reabsorbed initiating a shutdown of the survival response.
In the event that we remain in an extended stressed or threatened state, cortisol is released into our blood stream with the primary purpose of redistributing energy (glucose) to regions of the body that need it most so we can sustain the fight or flight response for a longer term. Cortisol slows down the body’s coping response so we don’t “gas out” quickly. Cortisol slows down our metabolism and increases abdominal fat retention, lowers pain sensitivity further and suppresses the immune system (so we don’t waste precious energy). But, if too much cortisol is released and unable to be reabsorbed, it overwhelms the system and begins to damage cells of the hippocampus, the part of the brain responsible for memory and spatial navigation.
TWO FORMS OF STRESS
We experience two kinds of stress: bodily and psychological. When our physical well-being or psychological well-being is threatened, our brain automatically activates our survival mode. Our amygdala doesn’t screen bodily threats from psychological threats or vice versa. It responds to both stressors the same way. So even while there might be no imminent physical threat to us, our mind can trigger a sustained physical response as a result of us fixating on a psychological stressor (real or imagined).
We are designed to handle bodily stress well, but not so well to handle mental or psychological stress. So holding a pessimistic or fearful approach to life or remaining in a high-stress home or work situation can result in many negative long term symptoms.
THREE SOURCES OF PSYCHOLOGICAL STRESS
There are three primary sources of stress. First, the unrelenting situation. This occurs when one is unsure when difficulty will arise and this state remains constant over time, such as chronic marital stress or difficulty with a coworker. Second, the high-stress responders. These are individuals who overreact emotionally to everything. As a result, they live in a constant state of alert and a body overwhelmed by adrenaline and cortisol. Third, the reactivators. These are individuals who retell and relive stressor events, and by doing so, activate the body’s alert response in the absence of any immediate external stress.
Look for the article titled, “Managing Stress” for ideas for how to combat stress.