Modern neurobiology recognizes the stress response of our autonomic nervous system (ANS) as a component of the powerful and complex system designed to assure our survival. Research across a range of sciences is demonstrating how the basic survival drive of our organism — and the neural circuitry through which it is expressed in the body — has in modern times become the root of a collectively shared set of chronic stress reactivity. Ironically, we now know this survival-driven stress reactivity undermines healthy physiological processes, and over time contributes to the chronic illness of body and mind we see in the majority of our patients. We aren’t talking about the emotional state of frustration, anger or exhaustion behind the statement “I am so stressed at work/home right now”. Rather, we’re highlighting what’s going on in the body to bring about those and other challenging emotions as a regular occurence and over long periods.
The Nature of the Stress Reaction
Our amazing human autonomic nervous system (ANS) has evolved over eons the highly sensitive ability to detect danger and opportunity in the environment and to signal effective physiological responses to both. These messages travel instantaneously to all parts of the body, prompting rapid defensive or offensive reaction in the case of danger or life threat, and in the presence of safe connection to others prompting a rest-and-digest and relate signal.
Beautiful Survival Adaptation
This capacity of our autonomic nervous system to detect danger and/or life threat and to prompt effective reaction has been central to our successful evolution over the eons. It has enabled our survival to pass on our genes for thousands of generations.
Here’s how it works:
The autonomic process of constant scanning for danger or safety has been named ‘neuroception’ by Dr. Stephen Porges, author of the Polyvagal Theory, to distinguish it from the mental process of perception. That is, it is a process constantly running outside of consciousness, like everything the ANS does to regulate involuntary body functions such as breathing, blood pressure, heartbeat, and the dilation or constriction of key blood vessels and small airways in the lungs. We don’t have to think about it.
Very broadly speaking, the ANS signals the body to react in one or the other of its two main modes: defense (which can express as aggression), when danger or threat is detected, and calm connection, when safety is detected. The ANS prompts this reaction by signalling the hypothalamus, the part of the brain that links the nervous system to the endocrine system. The detection of danger triggers the amygdala to send a distress signal to the adrenal glands. These glands in turn react by pumping the hormone epinephrine (also known as adrenaline) into the bloodstream. As epinephrine circulates through the body, it brings on a number of physiological changes:
- The heart beats faster than normal, pushing blood to the muscles, heart, and other vital organs.
- Pulse rate and blood pressure go up.
- Breath becomes more rapid.
- Small airways in the lungs open wide, enabling the lungs to take in as much oxygen as possible with each breath.
- Extra oxygen is sent to the brain, increasing alertness.
- Sight, hearing, and other senses become sharper.
- Epinephrine triggers the release of blood sugar (glucose) and fats from temporary storage sites in the body. These nutrients flood into the bloodstream, supplying energy to all parts of the body.
Survival Adaptation Gone Awry
All this reaction is aimed at ensuring survival of the threat via the defense mechanism of fight or flight. In order to mount this reaction, physiological resources are shunted away from resting processes like digestion and repair. For brief periods, while explicit danger is being overcome, this is very good. When the danger has passed, assuming survival, resting metabolism can resume. The stress reaction works extremely well in short bursts, followed by longer periods of rest.
Dangers of Modern Life
But the dangers of modern life are very different than those our ancestors faced. Our stresses tend to be constant, and for many of us the sympathetic fight or flight state is our default. Herein lies the problem.
Long-term activation of the stress-response system, and the overexposure to cortisol and other stress hormones that follows, can disrupt almost all our body’s processes. At the Plum Spring Clinic, we find this state to be a major contributor to our patients’ chronic health challenges, including:
- Digestive problems
- Heart disease
- Autoimmune and diseases of inflammation
- Disease of degeneration
- Sleep problems
- Weight gain
- Memory and concentration impairment
Simply put, the nervous system that is in a constant or near-constant state of arousal will have its faculties for digesting, absorbing, repairing — THRIVING — diminished. That’s because the stress hormones curb or reroute resources from functions that are ‘non-essential’ for fighting or fleeing, including digestion and repairing. Hence the slow progress of symptoms, and the difficulty of healing. Breakdown of healthy physiological systems is inevitable, giving rise to chronic symptoms that can become debilitating, and can also be the precursor to disease states.
At the Plum Spring Clinic, our experience has taught us that we can’t make significant inroads to healing chronic illness without ‘moving the needle’ on our patients’ chronic stress reactivity toward a default in the calm autonomic resting state. We have also developed deep respect for the truth that as mammals, we humans do not affect such change on our own. Rather the healing journey is most effectively supported by relationships of trust with a team that provides functional medicine and nutrition expertise to biochemical and physiological impairments, Somatic Experiencing to relieve the system of the burdens of past trauma, and coaching for resilience to stress. In this way, our team actualizes the commitment to addressing the roots of illness.