How Stress Affects Your Health
Updated: Nov 29, 2021
The Hungarian-Canadian endocrinologist, Hans Selye (1907-1982) was a pioneer in the field of stress and founder of the stress theory (in the usual every day or psychological or biological senses). He discovered the biological three-stage general reaction to external stress agents (which he called the ”stressors”) while experimenting on rats. This reaction is general (predictable). It is not specific to the stressor. He, therefore, called it the ”General Adaptation Syndrome” (G.A.S.) “nonspecific response of the body to any demand “ and extended it to humans and to other biological entities. Going a step further, he formulated the three-stage adaptation to such steadily renewed external stressors.
The 3 typical stages of the stress cycle - Fight - Flight - Freeze
1. The Alarm Stage Stress Physiology: Sudden shock or trauma triggers the release of epinephrine and norepinephrine, cortisol and DHEA. The body-mind shifts gear into high alert and survival mode.
A stressor disturbs homeostasis. The rate of all bodily functions of the autonomous nervous system increases dramatically to give us the physical strength to protect ourselves against an attack, or to mobilize internal forces. In normal circumstances the alarm reaction phase will not last for very long, in some instances, it may only be for a few seconds, in other instances longer.
2. The Resistance Stage Stress Physiology: The body attempts to adapt to long-term stress: cortisol is often unhealthily high, and DHEA levels low.
If the resistance/adaptation phase continues for a prolonged period of time without periods of relaxation, sufferers become prone to fatigue, concentration lapses, irritability and lethargy. At the most fundamental level of response, the organism is going to be either fighting or fleeing in some way, in an attempt to resist the negatively perceived consequences of the threatening stressor. This resistance may be required for either, a few moments, days, months, and sometimes even years. The form of resistance employed will have varying degrees of success depending on how well it is employed and how relevant it is in dealing with the stressor situation. Regardless of the length of time, once the threatening stressor has been dealt with effectively the organism is able to return to its pre-activated state and recover from the ordeal.
Every organism has restricted resources to adapt to stressors. Therefore, one will lose “adaptation energy”. It is through this process of adaptation that we learn how to cope better. Problems occur at the resistance/adaptation phase if the combined biological, psychological and social responses employed do not deal with the threat effectively or if the threat is chronic whereby it eventually wears down the capacity of the organism to resist the threat or deal with it properly. This problem leads us to the exhaustion phase.
3. The Exhaustion Stage
If the stressor environment is chronic and excessive without any real opportunity to recover or adapt successfully, the organism will begin to show signs of adaptation failure. Systems begin to break down and we become more susceptible to a range of biopsychosocial symptoms. If we persist in functioning at this level, death can occur.”
Stress Physiology: The adrenals can no longer cope and lack the vitamins, minerals and wherewithal to produce enough hormones. The thyroid is now under extra pressure to perform – sometimes becoming exhausted itself, e.g. with M.E./chronic fatigue and depression. There may also be fluctuations in blood pressure, digestive inflammation, blood sugar problems, vascular damage and muscle wasting.
The Adrenals and the HPA axis The HPA axis refers to a series of events triggered by stress affecting the hypothalamus, pituitary and adrenals. It results in the release of cortisol and aldosterone.
The hypothalamus is a gland in the brain that is referred to as a bridge between the endocrine system and the nervous system. Stress will trigger responses in both systems. The pituitary is often called the master gland of the endocrine system. It resides in the brain that releases a number of hormones, most of which are responsible for stimulating other endocrine glands to release their hormones.
Essentially, the hypothalamus secretes a hormone (Crh), which triggers the pituitary to release another hormone (ACTH), which triggers the adrenals to secrete cortisol and aldosterone. These two hormones will regulate blood pressure, the balance of sodium and potassium movement through cells and fluids and therefore levels of hydration, and also energy levels, mood and more.
The HPA axis works on a negative feedback loop, which means that when everything is in balance, a message will get sent back up the line to stop or slow down this activity.
The HPA axis also has a natural daily rhythm controlled by the hypothalamus, which is stimulated by light. All adrenal hormones have a circadian rhythm, that is to say, a day/night cycle. Cortisol, for example, tends to peak first thing in the morning. If cortisol is elevated at night time instead, then this can contribute to insomnia.
Stress and trauma can disrupt the HPA axis in a number of ways that scientists have found confusing to interpret. So although we might expect cortisol levels to be raised or lowered in response to certain events or conditions, they do not always follow this expected pattern.
For this reason, we cannot rely on laboratory tests to show what is going on – a holistic case history and mapping sequence of events will often be a more accurate indicator of how stress is affecting an individual.
The good news is, stress physiology is predictable. For this reason, we can proactively influence our response to triggers at the alarm phase through mind-body practices. In doing so develop greater resilience.
Adrenals and thyroid The thyroid’s functions are directly affected by adrenal imbalance, in particular cortisol levels. Low cortisol levels will slow down the conversion of thyroid hormone T4 to its more active form T3. High cortisol levels will disrupt the conversion so that something called reverse T3 is produced instead.
Orthodox medicine will only measure T4 (thyroxine) levels and sometimes TSH (thyroid-stimulating hormone) to assess thyroid status. However, a frequent pattern that these tests overlook is when levels of T4 are adequate or high, but the T4 is not being effectively converted to T3, so that T3 levels are low and reverse T3 levels are high. T3 is the more active form of thyroid hormone that we need to maintain proper thyroid function. High levels of reverse T3, on the other hand, have been linked to poor day-to-day physical and mental functioning, and many health professionals are looking to poor T4 to T3 conversion to explain a wide range of thyroid conditions and subsequent poor health.
ADRENALS AND REPRODUCTIVE HEALTH Poor thyroid function has repercussions for fertility, menstrual health and menopause. In addition, we have seen how DHEA is a precursor to sex hormones, and that adrenal depletion in general will use up resources for making other steroid hormones, including oestrogen, progesterone and testosterone.
Adrenals and blood sugar Cortisol increases the release of stored glucose into the blood and the conversion of muscle protein to glucose. Cortisol levels also directly affect the ability of cells to take glucose from the blood, with high cortisol levels resulting in high blood sugar levels. They do this by making the insulin receptors on the cell membranes less sensitive to insulin, the hormone released by the pancreas to trigger blood sugar uptake by the cells. The pancreas will often respond by producing more insulin – depleting further nutrients – and eventually may wear itself out, leading to Type 2 diabetes. The resulting excess blood sugar may then be converted into fat, which tends to be stored mainly around the hips, abdomen and thighs. If levels of cortisol are too low, then blood sugar will usually also be low, with potential symptoms such as light-headedness, energy dips or generally low energy, sudden hunger, irritability and disrupted sleep.
BASELINE SUPPORT It's easy to understand how stress impacts the adrenal, and how this can spiral out into a number of hormonal and general health issues. It is therefore important to first rebalance the adrenals with baseline support.
This would apply in most situations where there is an apparent hormonal imbalance with any aspect of the endocrine system – including low blood sugar, diabetes, thyroid conditions, insomnia, hyperactivity, period problems, menopause, fertility, mental health issues, lowered immunity and ME/chronic fatigue. It could be said that all chronic disease has inflammation at its root, and knowing how involved cortisol is here, we could also add heart disease, cancer, rheumatoid arthritis, Parkinson’s disease, Alzheimer’s disease, MS and much more to this list. Indeed, in many cases an adrenal, thyroid or other hormonal link has already been noted by the medical profession.
ADRENAL HORMONES & THE STRESS RESPONSE
The main hormones that your adrenals are responsible for releasing are:
ADRENALIN AND NORADRENALIN - frequently known as epinephrine and norepinephrine, These are your “fight or flight” hormones, and are non-steroid, which means they are structured around amino acids. They are made in the adrenal medulla, at the centre of the adrenal gland. CORTISOL This hormone increases blood sugar, is involved in the anti-inflammatory/immune response, and also assists with the metabolism of fat, protein and carbohydrates. It is a steroid hormone, which means it is structured around a cholesterol ring, and is also known as a glucocorticoid, as it is made in the adrenal cortex, the outer edge of the adrenals. DHEA (dehydroepiandrosterone) This is a precursor to sex hormones, and has been connected to anti-ageing and longevity. It is another steroid hormone produced in the adrenal cortex. SEX HORMONES (e.g. oestrogen and testosterone) These are involved in reproduction and male/female characteristics and are also steroid hormones made in the adrenal cortex. ALDOSTERONE This hormone is responsible for sodium retention in the kidneys, and it is released when blood pressure is low. by keeping sodium in circulation in the blood, it also keeps water circulating in the blood to keep blood pressure at the right levels. Aldosterone is also a steroid hormone produced in the adrenal cortex.
Adaption A typical response to stress is for cortisol and DHEA to be elevated, then to normalise afterwards. Long-term stress or poor adaption after periods of stress can result in long term elevation of cortisol and lowered DHEA. As we look at each of these more closely, you’ll be able to see what kind of an impact that may have.
“Fight or Flight " The hormones we think of first in relation to the adrenals are adrenalin and noradrenalin – also known as epinephrine and norepinephrine. These are your “fight or flight” hormones, and leap into action in times of stress, threat, trauma or exercise. Their role is simple: to activate and enhance the parts of you that are most useful in this moment for your survival. Included in this: • heart rate increases and strengthens – this is to increase blood flow to the muscles so that they have more oxygen and glucose to use for energy • blood vessels constrict – this raises blood pressure to similarly increase blood flow • bronchioles in the lungs dilate – to increase oxygen flow into the body • Fatty acids are released from fat cells (lipolysis) – to provide back-up energy as blood glucose reserves get used up; other hormones also break stored glucose (glycogen) down in skeletal muscle to provide more energy • Metabolic rate increases – to speed up production of energy from oxygen and glucose • Pupils dilate – to take in more light/ information • non-essential processes are downgraded – such as digestion, reproduction, tear and saliva production
These fight and flight processes use up a lot of resources.
To begin with, epinephrine and norepinephrine are part of a family of hormones called catecholamines and are made primarily from amino acids (and as such are called non-steroid hormones). To contract or dilate the heart, blood vessels, bronchioles and pupils, the muscles in each area need swift access to calcium and/or magnesium and energy. Many of these processes require enzymes to spark off local activity, which the body makes from amino acids plus a host of supporting vitamins and minerals.
Omega 3 essential fatty acids EPA and DHA also seem to play a role. A human study demonstrated that fish oil supplementation lowered the levels of catecholamines such as adrenalin/epinephrine released under conditions of mental stress. The researchers also found lowered levels of cortisol in the blood, lower rates of lipolysis and lower energy expenditure. So fish oil (or flax oil) would seem to counter the physical impact of stress.
CORTISOL Remember that with long term stress or poor adaptation to stress, cortisol levels often stay elevated. One of cortisol’s roles is to decrease bone formation, so there may well be implications with osteoporosis and similar conditions. In addition, high levels of cortisol and other glucocorticoids prevent the vitamin d receptors on our cells from taking up vitamin d3, and so the DNA in those cell is unable to respond to the triggers vitamin d3 provides for gene expression. So even if your blood serum vitamin d levels are ample, raised cortisol levels may prevent this from protecting you from the increasing number of chronic diseases vitamin d deficiency is associated with.
Cortisol also increases blood sugar through two different pathways: • Gluconeogenesis (making glucose in the liver from some amino acids, glycerol, lactate and/or propionate) • Glycogenolysis (making glucose from glycogen in liver and muscles), stimulated by epinephrine and norepinephrine If prolonged, high cortisol levels may also lead to muscle wasting, as muscular protein is broken down to make glucose. This is all to make more fuel available to muscles for fighting or fleeing a dangerous situation – but if you are sitting in your office chair feeling the effects of long term stress, then elevated blood sugar levels may contribute to all kinds of health problems, including diabetes. in addition, elevated cortisol levels will suppress the immune system by decreasing b-cell antibody production. Cortisol is an essential part of the anti-inflammatory process, which should ideally be a benefit.
Usually inflammation is a positive response to injury, trauma or irritation anywhere in the body. Part of the healing process requires inflammation to calm down again, and this is where cortisol comes in. Prolonged stress decreases tissue sensitivity to cortisol, so that inflammation becomes a long-term picture and potentially the backdrop to chronic disease.
In a recent study, for example, serum cortisol predicted increased mortality from cardiovascular disease in patients with acute coronary syndrome.
DHEA DHEA also seems to be involved in bone strength, and a 2006 study shows DHEA supplementation improves bone density in elderly women. So high cortisol and lowered DHEA may together be a contributing factor to osteoporosis. There is also the link between high DHEA and longevity. Okinawan men and women, for example, have higher levels of DHEA as they age than other populations on the planet, and they have among the highest levels of centenarians in the world. There have been a number of studies looking at the benefits of DHEA supplementation that point to some of the important roles DHEA plays. One study found that DHEA supplementation improved memory and mood, and also decreased cortisol levels.
Before heading straight for DHEA supplements, the naturopathic approach seeks to first return integrity to the adrenals so that they can make their own DHEA. This may be a sensible philosophy when approaching any hormonal disorder.
ALDOSTERONE Aldosterone is involved in regulating blood pressure. Aldosterone is released as a response to low blood pressure and instructs the kidneys to conserve sodium, and therefore water. by urinating less as a result, the blood sodium and fluid levels stay high, helping to maintain blood pressure. At the same time, potassium is lost. If aldosterone production falls, then too much sodium may be excreted in urine, leading to low blood pressure and salt cravings. If aldosterone secretion is too high, as has been noted with acute stress, then blood pressure will usually also be elevated.
Understanding your triggers, and cultivating relaxation, are important for developing resilience.
How do we recalibrate or reset stress physiology at the alarm or resistance phase? Early intervention and prevention are key to wellbeing.
Tune into episode 3 Wellbeing Wizards podcast for advice on effective techniques.
Working with Gee Gahir, a Pioneer of holistic wellbeing services within the NHS, and Co-founder of Wellbeing Wizards, a podcast platform that provides insights into transforming wellbeing, Gee is an accredited EMCC intuitive lifestyle coach providing preventative naturopathic mind-body-space solutions to facilitate vibrant health and balanced lifestyles.
Connect with Gee to arrange a personalised coaching experience.