Stress is something near and dear to my heart. I've spent much of my life in a state of heightened stress, awareness and vigilance. It is something so familiar to me that periods of relative ease have felt foreign, even threatening. As I've gotten older and just a little wiser, I've made an effort to get ever more familiar with stress. What is it? Why do we suffer with it? Why does it have to feel so awful!? I hope to at least touch on some answers to these questions and more importantly, I hope to demonstrate that stress is a positive thing, and that it is possible to befriend this response in order to build a happier and more sustainable life.
Most of us are well able to describe what stress feels like; physical tension, elevation in heart rate, irritability, sweatiness. We might describe periods of worry, an inability to focus or sit still. But none of that really tells us what stress is. It gives us a subjective impression of stress but nothing concrete to hold on to.
Stress is the body's response to a stimulus that demands some adaptation or change in behaviour in order to maintain allostatic load, the fluctuating equilibrium of the body. Think of it as a cup holding the components of our lives; maintaining our functioning bodies at their unique “optimum,” maintaining and managing social relationships, and the performance of our daily tasks from keeping our homes in good repair, dealing with traffic, grocery shopping and paying our bills. All of these life items have their space in the cup and make their demands on our capacity to meet them. As we add things to the cup, the cup gets more full. As the cup fills, we encounter the edge of our current stress capacity and attempt to stretch, or grow it. And when we begin to feel that way about it, irritable, tired, headachey etc, our capacity to stretch and grow begins to find the thinner margins.
The primary systems to enact the stress response are the endocrine system and the nervous system. These two systems actually work so closely together it would almost be worth considering them the neuroendocrine system, especially in the stress response. It begins with a stimulus that is received and appraised by the central nervous system. Your response is dictated by your genetics, history, current stress load, and general personality traits. Once threat has been determined, the response is swift and immediate. A hormonal cascade begins in the brain to activate both the nervous system and the hormonal system. Both begin at the same time but their effects occur on slightly different time-lines.
When something startles us, we may notice our skin prickles as each hair stands on end; this is our body's way of increasing our sensory perception, each hair feeling for subtle changes. We likely also notice our attention instantly zeroes in on what startled us. We note that our heart rate may increase with a sudden thundering in our chests. We may begin to breathe more rapidly in preparation for fighting or fleeing, or we may hold our breath in a sudden freeze. We may notice a funny feeling in our bowels or guts. These instant responses are all governed by the nervous system. In a sense we are on high alert looking for more information to inform our response.
Meanwhile, the hormonal system is rippling it's chemicals out through the body. The effects of the hormones are more delayed than the nervous system, perhaps taking a few second longer to initiate, and tend to last longer in their effect. Cortisol and epinephrine (adrenaline) are released into the blood stream and serve to perpetuate the changes initiated by the nervous system, ensuring that the stress response is activated long enough to keep us alive for as long as the threat is present. The changes to our cardiovascular system are maintained so we can run or fight, and the inhibiting of our parasympathetic nervous system (responsible for recovering, digesting and relaxing) is maintained so we aren't wasting precious energy on currently non-essential body functions. Should the stimulus be identified as not worthy of this response, the nervous system begins shutting down the response. Brain structures stop producing activating hormones and the adrenal glands stop secreting stress hormones so they can be cleared from the body. Cortisol and epinephrine last about 3 minutes in the blood stream and our body returns to systems as usual.
This is the basic process of an acute stress response; what happens in the moment of encountering something that has been identified as a threat and what our bodies do to get us out of harms way. It is an incredibly useful program that initiates without our telling it to and runs on auto-pilot without much input from us. Sufficiently uncomfortable, these programs provoke us to respond to something to either keep us safe, or to initiate change and growth. Without these changes in our bodies we wouldn't ever be compelled to eat, bathe, move away from a heat source, put on a sweater, call a friend when we are feeling blue or learn a new skill. In this way, the point of acute stress is to get us to respond to our environment to ensure our continued survival. Which is, obviously, important.
But what about when stress becomes more persistent? When we never feel like it's safe enough to relax our guard? Using my own life experience as an example, next blog entry discusses chronic stress, exhaustion and a new way of looking at managing stress.
Jeffery M. Lating, George S. Everly. Jr. (2013) A Clinical Guide to the Treatment of the Human Stress Response 3rd Ed.; New York, NY: Springer
Want to learn more? Check out these great YouTube videos by Dr. Robert Sapolsky, a well known and researched expert in human endocrinology, neuroscience and present day expert on human stress.