The biology of stress and the chemistry of our emotions
Updated: Mar 27
Stress is the silent epidemic of our time, having become a state of mind and way of life for too many of us. Yet stress doesn’t only reside in our heads. Although stress is certainly a feeling, it is also a biological response that we experience whenever we encounter a threat we feel we don’t have the resources to deal with. Such stress can be almost anything that upsets our equanimity: danger or disease, an exam or job loss, divorce or the death of a loved one. Ultimately, every cell in human body is an exquisitely sensitive barometer of our thoughts, emotions and perceptions – and any stress that disrupts our mind also disrupts our physical body.
The body is hard-wired to help us handle stress and cope with change. Whenever we experience stress – be it a physical, emotional or environmental event – the brain attempts to prepare the body by initiating a series of chemical reactions. At the core of this reaction is the hypothalamus-pituitary-adrenal axis, an interconnected network of endocrine glands that regulate the production of hormones including cortisol, adrenaline and norepinephrine.
At the first sign of a threat – whether real or imagined – our sympathetic nervous system triggers the release of chemicals that cause our heart rate to increase, our pupils to dilate, and energy to be directed toward the extremities. Digestion temporarily shuts down. All of this serves to direct more blood to our arms and legs so that if need be, we can either attack what is threatening us, or turn and run if it is too formidable. This “fight or flight” response is our body’s attempt to boost our chances of survival by increasing hormone levels, heart rate, breathing capacity and mental awareness. It’s also why we may feel agitated and literally want to run away from our problems during stressful times. Fight-or-flight is an instinctive response to life-threatening situations that represents a state of protective arousal in the body.
Stress becomes a serious and damaging health issue – rather than a life-saving response – when the brain is overwhelmed with stimuli that it perceives as an on-going, relentless threat. This might include a demanding boss or nasty co-workers, significant financial worry, an excruciatingly long daily commute, or an abusive spouse. This is when stress evolves from a temporary, life-saving response to a specific threatening situation (such as escaping a burning building) to a chronic, generalized dread toward life’s daily pressures.
Whenever we experience anxiety, fear, distress, depression or frustration, our thoughts trigger the release of the same stress hormones that would be activated if our life were in genuine danger. This alters the physiology of every cell in our body. The prolonged release of adrenaline can lead to tremors, insomnia, heart palpitations and premature aging. Chronically elevated cortisol levels have been shown to depress cartilage and bone formation, inhibit inflammation (and the immune system’s ability to fight off infection) and alter digestive function. Over time, the body may reach a state where it has exhausted its supply of stress hormones and suffer with adrenal fatigue. Ultimately, a continued state of stress depletes our reserves of vitality and energy, and interferes with our ability to fight off disease.
Breakthroughs in mind-body research show that the mind operates as a kind of interface between the body and the spirit. Emotions are the result of our interpretations of what we sense and what we believe, including our perceptions of and reaction to stress. The emotions we feel are not just sensations – they are a dynamic set of electrical, chemical and hormonal responses that express and reflect the stress we experience.
Emotions trigger a cascade of biochemical changes in our body that affect the way we function and how we feel. Our nervous and endocrine systems communicate bi-directionally through our immune system in the “language” of hormones and neuropeptides. This means that our emotions can induce health or illness. Discoveries in the field of applied psychophysiology and psychoneuroimmunology have documented many biochemical intersections between the body and mind related to our immune health. Some examples include:
Natural killer blood cells (NK cells) work to destroy tumors, diseased tissue and invading viruses/bacteria. NK cell levels are considered indicative of immune strength. Psychological stress has been found to reduce NK cells and increase disease severity.
Chronically raised cortisol levels – our “stress hormone” – have been found to contribute to high blood pressure, reduced mental performance, blood sugar issues, thyroid suppression and increased abdominal fat. A study of bereaved spouses showed they had elevated cortisol levels and decreased NK cells.
Immunoglobin A is an important antibody produced by white blood cells to battle foreign pathogens (such as bacteria) and support the immune system. Studies show that this antibody is at its highest level when we are calm and happy, and is significantly reduced when we are angry or fearful.
It might not surprise you that research reveals more heart attacks happen on Monday morning than any other time of the week, as the prospect of returning to a job that provides minimal-to-no satisfaction or joy takes a devastating toll on many of us.
Dr. Candace Pert, a brain researcher at Georgetown University Medical School, discovered what she calls the “molecules of emotion” – or neuropeptides – and how they translate our emotions into our body chemistry. She found the same chemicals that control mood in the brain also control tissue integrity throughout the body. Dr. Pert’s thesis rests on the fact that neuropeptides are found throughout the body, including the brain and the immune system. They are the means by which all cells in the body communicate with one another. Neuropeptides and their receptors link the brain, our glands and immune system in a network that allows the brain and body to communicate, and represents the biochemical substrate of our emotions.
Nearly a century before Dr. Pert’s ground breaking research, Harvard University physiologist Walter Cannon first proposed the now fully accepted notion that our body has a state of homeostasis: a self-maintaining, harmonious condition that responds to internal and external environmental factors. Maintaining homeostatic balance is crucial if we hope to achieve optimal health (Indeed, Chinese medicine is based on this same fundamental principle). Anything that disrupts the body’s natural balance can be considered stressful. Disease results when factors, either internal and/or external, persistently disrupt our balance and keep us from adapting to our environment. Stress is, by Cannon’s definition, an imbalance of the mind–body equilibrium. And chronic stress makes it virtually impossible to maintain homeostasis. As ongoing and unresolved anxiety, fear, anger and sadness trigger the stress response, our heart rate will remain elevated while our digestive and immune systems shut down. Over sustained periods of stress, the body’s ability to properly digest, eliminate and ward off infection is undermined.
William James, the father of modern psychology, famously asserted that the greatest weapon we have against stress – and its deleterious effects on the body – is our ability to choose one thought over another. He understood that stress is ultimately subjective – a fluid experience that depends on how we perceive and respond to the events in our lives. When we face long-term stress with an attitude of helplessness, pessimism or frustration, these negative feelings interfere with the body’s innate restorative capabilities (as we become less and less able to “turn off” the fight-or-flight response). The on-going release – and eventual depletion – of stress hormones depresses production of antibodies and erodes the immune system. Alternately, if we approach stress with a positive attitude, viewing it as a challenge to be overcome, we can enhance our natural, restorative capabilities and dramatically improve our physical health.
At the turn of the twentieth century, James wrote, “The greatest discovery of my generation is that human beings can alter their lives by altering their attitudes of mind.” Since then, numerous studies have confirmed that personality patterns appear to play a role in the development of specific diseases. Even an early study by Harvard University researchers in 1937 found that individuals who typically handle stress and strain in an “immature way” became ill four times more often than those who did not. Their chief coping style, projection – unconsciously disavowing their own conflicting feelings by identifying them in the behavior of others – was like that of children.
To adequately deal with the stress we associate with modern day life, it is critical to gain control of our thoughts and master our emotions. All of my clinical experience has persuaded me that no other single factor is more beneficial to our overall health. No diet, exercise or even good night’s sleep will effectively reduce or eliminate the stress we each face in life as much as altering our own perception of the stressful situation. I would argue that this discovery is as significant as hand washing was to prevent bacterial and viral infection a century ago.
According to Chinese medical theory, the strong emotions often associated with stress constrict the flow of vital energy – or Qi – throughout the body. When these feelings and attitudes persist over long periods of time, they create a blockage in the body’s energy flow. This is often diagnosed as Liver Qi Stagnation and can manifest as mood swings (including agitation, depression, anger or frustration) digestive disorders (such as diarrhea, constipation, IBS or nausea) and menstrual disharmonies (including PMS, pain and cramping, and irregular periods). Chinese medicine focuses on unblocking the flow of energy and restoring balance within the body by soothing liver Qi, tonifying liver blood and spleen Qi, and clearing heat in the heart and liver. Acupuncture increases the circulation of blood and oxygenates the tissues throughout the body while cycling out cortisol and releasing natural pain-killers called endorphins. Other benefits of acupuncture include decreasing the heart rate, lowering blood pressure, and relaxing the muscles to help the body feel less stressed.
Because of its ability to modulate the nervous system, acupuncture is one of the most effective remedies to combat stress, anxiety and depression. In particular, acupuncture down-regulates activity in the limbic system, making it a powerful method to naturally reduce stress. Research studies have shown that acupuncture reduces many of the common markers of stress – including hormones and neurotransmitters – that are present in the blood when we are under stress. Numerous studies have also show that acupuncture is effective in treating Post Traumatic Stress Disorder (PTSD), one of the most severe and debilitating manifestations of chronic, unresolved stress.
In addition to acupuncture, there are hundreds of natural substances within the Chinese herbal materia medica that are specifically designed to work on balancing the body to reduce stress. Adaptogens are a unique group of Chinese herbs used to improve the health of our adrenal system, the system that’s in charge of managing the body’s hormonal response to stress. They help strengthen the body’s response to stress and enhance its ability to cope with anxiety and fight fatigue. They’re called adaptogens because of their unique ability to “adapt” their function according to the body’s specific needs. Though the effects may initially be subtle and take time to make themselves felt, they’re real and undeniable.
One of the most commonly prescribed Chinese herbal formulas to relieve stress is Xiao Yao San (as known as Free and Easy Wanderer). This herbal combination is effective at smoothing the flow of Qi in the body, harmonizing digestion, and strengthening the blood.
Exercise should also be a part of everyone’s stress management plan, as it helps the body produce more endorphins (sometimes called “runner’s high”). Many types of physical activity can stimulate this response – each person should find the type of exercise that’s right for him or her. For some, walking is enough. Others will want to get more of a workout to get their blood pumping and break a sweat. Qi gong, yoga and meditation are all forms of mind–body exercises that have been shown to help induce relaxation by making the heart beat slower, muscles relax, breathing become slower, and blood pressure decrease.
Chronic stress is like an alarm system that won’t stop ringing. It burns through our critical energy reserves, depletes our key hormones, and wastes our cellular resources. A 2011 study of long-terms patterns of stress and its effect on longevity determined that individuals with moderate-to-high stress levels die at younger ages than those with lower stress.
There is no under-estimating the significant role that stress plays in our health and well-being. Stress is a major factor in the development and progression of the vast majority of diseases, including heart disease, diabetes and cancer. Even so, the significance of stress is often overlooked and unappreciated by doctors and patients alike.
Ultimately, stress is a unique and subjective experience for each of us. But no matter the source of the stress in our lives, it will negatively impact our mental and physical well-being if it is allowed to disrupt our internal balance for an extended period of time. No matter how we define stress, restoring our equanimity and balance after a stressful event is the key to staying healthy.