Stress has become a defining feature of modern life, with the phrase ‘I’m stressed’ an everyday euphemism for various states of physical and emotional distress, from anxiety, worry or fear, to exhaustion, grief or depression. From a medical perspective: “Stress is defined as an organism’s total response to environmental demands or pressures…Stress in humans results from interactions between persons and their environment that are perceived as straining or exceeding their adaptive capacities and threatening their well-being” .
It is interesting, from an integrated wellbeing viewpoint, to consider the etymology of the word ‘stress’ which is thought to derive originally from the Latin word ‘strictus’, which translates as ‘drawn tight’ .
In simple terms, stress is the body’s response to a particular trigger, or ‘stressor’. So stressors (also known as triggers) are essentially any episode, activity or event which induces stress. Stress is associated with our autonomic (independent) nervous system, which operates largely outside conscious thought. The autonomic nervous system is sub-divided into the sympathetic and parasympathetic divisions; the sympathetic division is unconsciously activated in response to a stressor, to prepare the body for action in the face of a threat. This mode is commonly known as the ‘Fight or Flight’ response; more recently a third ‘freeze’ option has been added, so it is now also referred to as ‘the Three F’s.
The arousal of the sympathetic nervous system is deep rooted, involving primitive areas of the brain such as the hypothalamus, brain stem and spinal cord. So it is likely this physiological response evolved thousands of years ago, when as humans, we faced considerable threats to our survival.
In general terms, the sympathetic nervous system prepares the body for physical effort, whether fighting, running away (flight), or coming to complete stillness in the face of a threat. Stress hormones, adrenaline and cortisol are released by the adrenal gland; indeed, these are useful in studying an individual’s stress response. Blood and oxygen are diverted away from skin and the more superficial organs, such as digestion and kidneys, and routed to the heart and lungs. The digestive system slows or ‘shuts down’, and bladder and sphincter muscles constrict. Respiratory vessels dilate to allow increased oxygen flow. The pupil dilates and the lens adjusts to better focus on objects in the far distance – not ideal when you’re operating a screen or machinery.
Stress can be extremely damaging in the long-term, if it is experienced at significant levels, over a prolonged timeframe, without a counteracting process to help alleviate the heightened state. In essence, the body becomes ‘locked’ in a perpetual state of sympathetic nervous system activation. This state of ‘chronic’ stress is regarded as a key determinant of diseases and disorders, whilst many others are aggravated by stress. Consider the connotation of the word: Dis-Ease. Indeed (and perhaps shockingly), it is now believed that 80-90% of all disease could somehow be linked to stress, including heart disease and strokes, hypertension (high blood pressure), increased risk of kidney or heart failure, and heart attack. Stress can suppress the immune system, causing susceptibility to infections and autoimmune diseases like arthritis and multiple sclerosis. It can exacerbate allergic reactions, triggering asthma and other allergy related conditions, skin problems like eczema and psoriasis, acne and rashes. Stress can also cause muscular pain and spasms due to prolonged contraction, especially in the back, shoulders and neck; headaches and migraines; stomach disorders such as ulcers, and insomnia. It has further been linked to diabetes and infertility.
As well as physiological issues, stress can have a significant behavioural impact. In its guide to identifying stress, the Health & Safety Executive highlights a range of behavioural symptoms as potential indicators of stress, including (but not limited to) “irritability and aggression, changes in eating habits, increased tendency to self-medicate with caffeine, alcohol, tobacco and drugs, becoming less co-operative, sociable, even more accident-prone” .
References/Citations: http://medical-dictionary.thefreedictionary.com/stress  http://www.oxforddictionaries.com/definition/english/stress  http://www.workstress.net