By

Larissa Gough

Stress is any stimulus of the nervous system, usually (but not always) of an unpleasant nature, to which the body or mind is subjected.  This might include such varied factors as intense heat or cold, inadequate nutrition (deficiencies or accesses), inadequate physical activity (too little or too much, or wrong kind of exercise), excessive noise, emotional states, drugs, pollution, etc.  Much stress comes from outside the body (stimulus from the external environment), but it may often be self-generated (stimulus from the internal environment) such as poor posture (mechanical stress) and shallow breathing (respiratory stress).

Any stress factor can cause the reactions of the body-mind complex, which are often described as fight-or-flight response, the primitive response to danger in which immediate preparation is made by the body to either defend itself (fight), or run away (flight).  Large numbers of physiological changes take place, which include: the brain and nervous system become intensely active, the digestive process stops, the saliva stops and the mouth becomes dry, the muscles tense in preparation for activity and the heart pumps blood harder and faster in anticipation of the extra activity, blood pressure arises, breathing becomes faster, hormones such as adrenaline are released into the system, as is glucose (from the liver), sweating commences in response to the need to cool the body, etc.

If the stress factors are rapidly removed then no harm is done and all the physiological changes are reversed.  Equally, if a valid response of a fight or flight nature is forthcoming (running away from an angry dog or punching a potential mugger) then the physiological changes will have been used appropriately, and normality will return. Such responses are, however, not appropriate to most modern stress situations such as difficult personal relationships, excessive pressure due to deadlines, financial anxieties, inability to communicate feelings, personality problems (self doubt etc.), dramatic lifestyle changes etc.  If stress factors are constant, or repeated frequently, and there is no release of the built-up of tension, or an adequate rest phase from the physiological changes described, then a variety of physical and mental symptoms will arise, including stiff aching muscles, backaches, headaches, dizziness, insomnia, anxiety, depression, hypertension, circulatory and heart problems, breathing difficulties, including asthma, digestive disorders, including ulcers, allergies, blood sugar irregularities (high or low), bowel disorders (constipation, diarrhea, colitis), skin disorders, sexual difficulties, etc. All of these can result from other causes, of course, but often appear when there is a prolonged exposure to stress.

Stress is not always unpleasant, but often accompanies many apparently pleasant events such as holidays – anything that alters the status quo.  Any change requires an adaptive response on the part of the individual, and this is regarded as stressful.

Initially the self-regulating mechanisms of the body, which maintain internal balance (homeostasis), will cope adequately with stress. Eventually, after months or years of prolonged or frequently repeated stress, the ability of the body to adapt, or cope adequately, will become impaired, the breakdown of the internal balance will begin and the symptoms will appear.