Fight or Flight Response and the Impact on Health
Introduction
When our body's balance is disrupted by physical or mental triggers, we experience stress. These stressors initiate a response involving changes in behaviour and body functions, orchestrated by the nervous, hormonal, and immune systems.
This intricate response prepares us to tackle challenges by activating the sympathetic-adreno-medullary axis, the hypothalamic-pituitary-adrenal (HPA) axis, and the immune system. For instance, our body's reaction to injuries or surgeries aims to prevent further harm. However, excessive, repeated, or prolonged stress can be detrimental, leading to conditions such as depression, anxiety, memory problems, and heart disease.
Not all stress is harmful. Some stress, known as "eustress," can be positive, invigorating, and inspiring, enhancing cardiovascular health, endurance, and cognitive function. Conversely, distress negatively impacts the body and mind. Physical stress triggers two key systems: the HPA axis and the sympathetic nervous system.
Cortisol, a stress hormone, plays a significant role by increasing adrenaline, reducing insulin levels, and mobilising stored energy. It also dampens the immune response, potentially slowing healing. Elevated cortisol can lead to the death of B-cells, crucial for immunity, while aldosterone helps maintain blood pressure by regulating sodium and water.
The brain's receptors manage these hormones' effects, ensuring energy conservation and stress management by reducing inflammation, slowing growth, and removing damaged cells.
Stress can manifest in various forms:
Chu et al. (2022). Physiology, Stress Reaction. StatPearls.
Acute stress: is short-term stress that typically results from immediate stressors or challenging situations. The body's fight-or-flight response leads to temporary physiological changes such as increased heart rate and adrenaline release.
Chronic stress: occurs when the stressor persists over an extended period. Prolonged exposure to chronic stress can lead to cumulative physiological and psychological effects, increasing the risk of health problems such as cardiovascular disease, anxiety, depression, and widespread pain.
Episodic acute stress: occurs when individuals experience frequent episodes of acute stress. This pattern may be characteristic of individuals who lead chaotic or disorganised lifestyles, constantly facing deadlines, commitments, or interpersonal conflicts. The cycle of stress exacerbates health issues and impairs daily functioning.
Traumatic stress: results from exposure to traumatic events, such as natural disasters, accidents, or violent acts. The trauma overwhelms an individual's ability to cope and may lead to symptoms of posttraumatic stress disorder (PTSD).
Environmental stress: arises from adverse or challenging conditions in one's surroundings, including noise, pollution, overcrowding, or unsafe living conditions. These stressors can have detrimental effects on physical and mental health, contributing to a sense of discomfort or unease.
Psychological stress: stems from cognitive or emotional factors, such as perceived threats, worries, or negative thoughts. Typical stressors include work-related pressures, academic expectations, social comparisons, or self-imposed demands.
Physiological stress: refers to the body's response to internal or external stressors that disrupt homeostasis. Examples include illness, injury, sleep deprivation, or nutritional deficiencies, which activate physiological stress pathways and compromise health and wellbeing.
Organ Systems Involved
Stress generally affects all body systems, including the cardiovascular, respiratory, endocrine, gastrointestinal, nervous, muscular, and reproductive systems. The endocrine system increases the production of steroid hormones, including cortisol, to activate the body's stress response. In the nervous system, stress triggers the sympathetic nervous system, prompting the adrenal glands to release catecholamines (a group of chemicals). Once the acute stress-induced crisis subsides, the parasympathetic nervous system aids in the body's recovery.
Cardiovascular System
Acute stress causes an increase in heart rate, stronger heart muscle contractions, dilation of the heart, and redirection of blood to large muscles. In contrast, chronic stress induces sustained activation of the sympathetic nervous system and HPA axis, leading to elevated levels of stress hormones such as cortisol and epinephrine. These stress hormones cause damage to cells, problems in blood vessels, and inflammation. This can lead to the buildup of plaque in the arteries and increase the risk of heart disease.
Respiratory System
The respiratory and cardiovascular systems are vital for supplying oxygen to our cells and getting rid of carbon dioxide. When we experience stress, it can disrupt how our autonomic nervous system works. This disruption can cause physical effects like narrowing of the airways and inflammation in the body. Acute stress can even change how we breathe, making our breaths shorter and faster, which worsens respiratory symptoms. Long-term stress also weakens our immune system, making us more likely to get respiratory infections and making conditions like asthma worse.
Gastrointestinal System
When we're stressed, hormones like adrenaline and noradrenaline are released and affect our digestive system. These hormones attach to receptors in the gut, slowing down digestion and reducing movement in the intestines. They also narrow blood vessels in the digestive tract, which lowers blood flow, reduces secretions, and makes it harder to absorb nutrients. Stress can cause diarrhoea or constipation and make the gut more sensitive, leading to issues like irritable bowel syndrome (IBS). Stress disrupts the connection between the brain and gut, making digestive problems worse and causing changes in gut bacteria.
Musculoskeletal System
Chronic stress sets off a series of bodily reactions, like releasing stress hormones such as cortisol and catecholamines, which affect the muscles and bones. Persistently high cortisol levels can lead to muscle loss and weaker bones by slowing down the cells that build bones and speeding up those that break them down. Additionally, the stress-triggered sympathetic nervous system can increase muscle tension and pain, leading to tension headaches, jaw disorders, neck pain and chronic low back pain. It can also delay healing and raise the risk of developing conditions such as fibromyalgia and chronic pain syndrome.
Immune System
When stress lasts a long time, it activates the sympathetic nervous system and HPA axis. This can weaken our immune responses due to high levels of cortisol, which makes us more likely to get infections and slows down healing. Also, chronic stress can lead to inflammation throughout the body, which contributes to autoimmune diseases and long-term inflammatory problems.
Reproductive System
Chronic stress can upset the balance of hormones needed for reproduction by lowering the release of key hormones from the brain. This affects the release of other hormones needed for ovarian function in women and testosterone production in men. As a result, women might experience irregular periods, difficulty ovulating, and infertility, while men might have reduced sexual desire, erectile problems, and poor sperm quality. Stress-related hormone changes can also lead to conditions like polycystic ovary syndrome in women.
Voxel-Man. (2001). Digital Anatomy of the Torso and Internal Organ.
Related Testing
Biological markers: Assessing stress hormones such as cortisol, epinephrine, and norepinephrine levels in the blood, saliva, and urine provides objective indicators of the physiological stress response. These markers reflect the activity of the HPA axis and the sympathomedullary pathway.
Heart rate variability: Heart rate variability analysis assesses the variation in the time interval between consecutive heartbeats, reflecting the balance between the sympathetic (fight-or-flight) and parasympathetic (relaxation) nervous systems. Decreased heart rate variability is associated with sympathetic dominance and increased stress levels, whereas higher heart rate variability is associated with stress resilience and improved cardiovascular health.
Blood pressure and heart rate: Monitoring changes in blood pressure and heart rate provides insights into cardiovascular responses to stress, including increased sympathetic activation and vasoconstriction.
https://thebloodcode.com/longevity-and-your-heart-rate-variability/
General Adaptation Syndrome
General adaptation syndrome provides a framework for understanding the physiological responses to stress and the potential consequences of chronic stress on health and well-being. The syndrome describes the different stress-induced physiological changes through 3 different stages, with the last 2 stages showing the harmful changes of extended stress. This syndrome is divided into the alarm stage, resistance stage, and exhaustion stage. The alarm stage refers to the initial symptoms of the body under acute stress and the fight-or-flight response. After the initial shock of the stressful event, the body begins to repair itself by lowering cortisol levels and normalising physiologic reactions such as blood pressure and heart rate. During this recovery phase, the body remains alert until the stressful event is no longer triggering. However, if the stressful event persists for extended periods, the body adapts to cope with higher stress levels. The body continues to secrete stress hormones, which maintain the body's elevated physical response to stress. This mechanism induces the resistance stage and includes symptoms such as poor concentration, irritability, and frustration. If the stressful event persists, the body enters the exhaustion stage. Symptoms of this stage include burnout, fatigue, depression, anxiety, and reduced stress tolerance. As the stressful event persists, the body's immune system weakens due to the suppressive effects of stress hormones on immune system cells.
General Adaptation Syndrome (Selye, 1946).
Steps to heal the autonomic nervous system
Nutrition
The autonomic nervous system can be influenced by what we eat, specifically by fats and proteins. Fats found in oils, butter, and meat, along with proteins from foods like meat, beans, and eggs, are crucial for building and repairing our body's tissues. When we consume fats and proteins, they quickly activate the autonomic nervous system through the vagus nerve pathway. This activation leads to the release of acetylcholine, which helps reduce the release of inflammatory substances in the body. This nutritional approach with dietary fats has been shown to effectively reduce overall inflammation, protect tissues, and maintain gut health. Studies have also found that a low-carbohydrate ketogenic diet can alleviate chronic pain by reducing inflammation, oxidative stress, and nervous system sensitivity. Additionally, adopting a whole-food diet that limits highly processed foods is an effective strategy for managing pain.
Meditation
Meditation and yoga are linked to feeling better mentally and physically. They reduce stress reactions like anxiety and avoidance behaviors. They also seem to boost the immune system, reduce inflammation, and calm the nervous system. For people with chronic pain or fibromyalgia, they can improve their quality of life. Yoga, especially, counteracts the body's stress response by promoting relaxation and focusing on the present moment. This shifts the body from a tense, ready-to-react state to a calm, healing state. Yoga can strengthen muscles, increase flexibility, improve breathing and heart health, and help with sleep. Overall, these practices enhance well-being and make life better.
Deep breathing
Continued slow breathing training improves autonomic function. The results of those previous studies are divided. Slow breathing increased vagal nerve activity and decreased sympathovagal balance activity, but there was no change in sympathetic nerve activity. Resting blood pressure changes with slow breathing as it reduces both systolic and diastolic blood pressures. Try slow deep breathing in the supine position for 10 minutes each day, either upon waking and/or before bed. Slow breathing can be performed under the conditions of exhalation at 6 seconds and inspiration at 4 seconds.
Vagus nerve stimulation
The term "vagus nerve stimulation" refers to any method that activates the vagus nerve. This can be done manually or with electrical devices. Left-side neck stimulation is approved to treat epilepsy and depression, while right-side stimulation helps with heart failure. Research suggests they're safe for epilepsy, depression, and pain relief. Transcutaneous electrical nerve stimulator devices have two flat surfaces that send electrical signals near the vagus nerve. They're placed on the neck where the pulse is felt, and users can adjust the intensity. Each session lasts about 90 seconds. Some people find pain relief with occasional use, but the device can also be used multiple times daily for prevention. A transcutaneous electrical nerve stimulator can be purchased from Amazon by clicking here.
Exercise
Aerobic exercise can increase the activity of the parasympathetic nervous system and reduce sympathetic activity. In contrast, heart disease often involves reduced parasympathetic activity and a heightened sympathetic tone. Research suggests that exercise, by restoring normal nervous system function, may improve outcomes in various conditions. Those with autonomic disorders typically have lower levels of maximal oxygen consumption, indicating reduced fitness and exercise capacity. There is strong evidence that some of the protective and therapeutic effects of regular exercise are linked to its impact on the autonomic nervous system. Additionally, exercise-induced improvements in vascular health, cardiac function, insulin sensitivity, and kidney function contribute to the treatment and prevention of cardiovascular, metabolic, and autonomic disorders. Exercise also enhances mental health, helps prevent depression, and promotes positive self-esteem. Moderate-intensity exercise for at least 30 minutes a day, five days a week, is recommended for most people to achieve these benefits.
Music
Listening to theta-frequency binaural beats boosts relaxation after exercise by enhancing parasympathetic activation and reducing sympathetic activity. Just 20 minutes of these beats significantly increase HF power, a marker of parasympathetic activity driven by brain activity. Even a brief exposure (<2 minutes) to theta-frequency beats can shift the autonomic nervous system towards increased parasympathetic dominance. Binaural beats create an auditory illusion when two slightly different tones are heard separately in each ear through headphones. For instance, if one ear hears 510 Hz and the other 500 Hz, the brain perceives a 10 Hz beat. Research also shows that 528 Hz music affects the autonomic and endocrine systems, with potent stress-reducing effects observed after just five minutes of exposure. An example can be found by clicking here.
Grounding (earthing)
Grounding or earthing means making direct contact between your skin and the earth's surface, like walking barefoot on grass or sand. This practice is known to improve health and make people feel better. Research has shown that when our bodies touch the earth, it can reduce inflammation, boost the immune system, help wounds heal faster, and even treat chronic diseases like arthritis. Studies suggest that grounding is a simple and natural way to fight inflammation and improve health. Just like batteries need to be recharged, our bodies benefit from reconnecting with the Earth's surface to stay healthy. For instance, some studies have found that 30 minutes of grounding can significantly reduce pain. After a week of daily grounding, pain levels in some people dropped by 80%, and in two weeks, some became completely pain-free. This happens because when we connect with the Earth, it lets electrons from the Earth flow into our bodies, which could have healing effects.
Biological Science (2nd Edition) by Scott Freeman (2005).
For those in the area, seeking chiropractic care in Abingdon can be an effective way to manage stress-related symptoms. A chiropractor in Abingdon can provide personalised chiropractic treatment to alleviate pain and improve overall health. Whether you're dealing with acute or chronic stress, Abingdon chiropractic services can help restore balance and enhance your well-being.
An experienced Abingdon chiropractor can tailor a treatment plan to your specific needs, supporting your journey towards better health. Chiropractic care not only addresses physical ailments but also promotes mental and emotional wellness, making it a valuable component of a holistic approach to health.
For comprehensive chiropractic treatment in Abingdon, consider visiting a local chiropractic in Abingdon to explore the benefits of chiropractic care in managing stress and improving overall quality of life. The chiropractor Abingdon community offers a range of services designed to support your health and well-being.
AUTHOR
Karl Robins (Chiropractor and Founder)
Focus Chiropractic is a trusted health care provider in your community, specialising in enhancing spinal function, alleviating pain, and offering prevention and wellness strategies for a healthier life. If you have any questions or need guidance, leave a comment below or email karl@focuschiropractic.co.uk.