stress

stress is a word derived from the Latin word stringere, meaning to draw tight, and was used in the seventeenth century to describe hardship and affliction. During the late eighteenth century (as Hinkle records), stress denoted ‘force, pressure, strain, or strong effort’, referring primarily to an individual, or to the individual's organs or mental powers.

Definitions of strain and load used in physics and engineering eventually began to influence our understanding of how stress affects individuals and their health. Under this concept, external forces (load) are seen as exerting pressure upon an individual, producing strain. Proponents of this view felt that they could measure the stress to which an individual is subjected, in the same way we can measure physical strain on a machine. While this concept looks at stress as an outside stimulus, an alternative concept defines stress as a person's response to a disturbance. As early as 1910, Sir William Osler explored the idea of stress and strain causing ‘disease’, when he saw a relationship between chest pains (angina pectoris) and a hectic pace of life. The idea that environmental forces could actually cause disease rather than just short-term ill health effects, and that people have a natural tendency to resist such forces, was seen in the work of Walter B. Cannon in the 1930s. Cannon studied the effects of stress in animals and people, and in particular studied the ‘fight or flight’ reaction. Through this reaction, people, as well as animals, will choose whether to stay and fight or try to escape when confronting extreme danger. Cannon observed that when his subjects experienced situations of cold, lack of oxygen, or excitement, he could detect physiological changes such as emergency adrenaline secretions. Cannon described these individuals as being ‘under stress’.

One of the first scientific attempts to explain the process of stress-related illness was made in 1946 by physician Hans Selye, who described three stages an individual encounters in stressful situations: (i) alarm reaction, in which an initial phase of lowered resistance is followed by countershock, during which the individual's defence mechanisms become active; (ii) resistance, the stage of maximum adaption and, hopefully, successful return to equilibrium for the individual. If, however, the stress agent continues or the defence mechanism does not work, he will move on to a third stage; (iii) exhaustion, when adaptive mechanisms collapse.

Critics of Selye's work say it ignores both the psychological impact of stress on an individual, and the individual's ability to recognize stress and act in various ways to change his or her situation.

Newer and more comprehensive theories of stress emphasize the interaction between a person and his or her environment, describing it as a response to internal or external pressures which reach levels that strain physical and psychological systems beyond their coping capacities.

In the 1970s Richard S. Lazarus suggested that an individual's stress reaction ‘depends on how the person interprets or appraises (consciously or unconsciously) the significance of a harmful, threatening, or challenging event.’ Lazarus' work disagrees with those who see stress simply as environmental pressure. Instead, the intensity of the stress experience is determined significantly by how well people feel they can cope with an identified threat. Any person who is unsure of his or her coping abilities, or is likely to feel helpless and overwhelmed.

Similarly, Tom Cox and colleagues in the late 1970s rejected the idea of looking at stress as simply either environmental pressures or physiological responses; they suggest that it can best be understood as ‘part of a complex and dynamic system of transaction between the person and his environment’ and criticize the mechanical model of stress: ‘Men and their organizations are not machines … Stress has to be perceived or recognized by man. A machine, however, does not have to recognize the load or stress placed upon it.’

By looking at stress as resulting from a misfit between an individual and his/her particular environment, we can begin to understand why one person seems to flourish in a certain setting, while another suffers. Tom Cummings and Cary Cooper in 1979 explored the stress process in a cybernetic framework as follows:(i) Individuals, for the most part, try to keep their thoughts, emotions, and relationships with the world in a ‘steady state’.(ii) Each factor of a person's emotional and physical state has a ‘range of stability’, in which that person feels comfortable. On the other hand, when forces disrupt one of these factors beyond the range of stability, the individual must act or cope to restore a feeling of comfort.(iii) An individual's behaviour aimed at maintaining a steady state makes up his or her ‘adjustment process’, or coping strategies.Accordingly, a stress is any force that puts a psychological or physical factor beyond its range of stability, producing a strain within the individual. Knowledge that a stress is likely to occur constitutes a threat to the individual. A threat can cause a strain because of what it signifies to the person.

Stress certainly involves a range of bodily reactions. Man is the product of many thousands of years of evolution, and to survive required a quick physical response to dangers. The body developed the ability to ‘rev-up’ for a short time. Cannon described this mobilization of forces as the ‘fight or flight’ reaction mentioned earlier. Primitive man expended this burst of energy and strength in physical activity, such as a life and death struggle or a quick dash to safety.

Modern man has retained his hormonal and chemical defence mechanisms through the millenia. But for the most part, the lifestyle in the Western world today does not allow physical reaction to the stress agents we face. As Albrecht pointed out, attacking the boss, hitting an insolent customer, or smashing an empty automatic cash dispenser are not solutions allowed by contemporary society. Even the non-aggressive ‘flight’ reaction would hardly be judged appropriate in most situations. The executive who flees from a tense meeting, and the assembly worker who dashes out in the middle of a shift, will likely suffer the consequences of their actions. Our long-evolved defence mechanisms prepare us for dramatic and rapid action, but find little outlet. The body's strong chemical and hormonal responses are then like frustrated politicians: all dressed up with nowhere to go, as Melhuish describes it.

It is this waste of our natural response to stress which may actually harm us. Although scientists do not fully understand this process, our thought patterns regarding ourselves and the situations we are in can trigger widespread physiological changes, acting through the hypothalamus — the part of the brain which co-ordinates a complexity of neural and hormonal mechanisms for taking care of bodily functions. In a situation of challenge, tension, or pressure, the hypothalamus activates both the sympathetic branch of the autonomic nervous system and certain hormone secretions from the pituitary gland. The resulting release of adrenaline and other hormones, together with other actions of sympathetic nerves, enhances the level of arousal and stimulates the cognitive, neural, cardiovascular, and muscular systems, whilst also mobilizing metabolic fuels to provide energy for an increase in muscular activity. These physiological changes are designed to improve the individual's performance: the heart speeds up and beats more strongly; this and widening of muscle blood vessels increase the blood supply of the muscles; breathing rate and depth increase. Blood pressure rises, and less blood flows to the stomach and the intestines, as well as the skin, resulting in the cold hands and feet often associated with a nervous disposition.

All of the body's ‘rev-up’ activity is designed to improve performance. But if the stress which launches this activity continues unabated, researchers believe, the human body begins to weaken as it is bombarded by stimulation and stress-related chemicals. As stress begins to take its toll on the body and mind, a variety of symptoms can result. We have identified physical and behavioural symptoms of stress occurring before the onset of serious stress-related illnesses; these include: insomnia, eating difficulties, breathlessness without exertion, a tendency to sweat with no good reason, frequent intestinal difficulties, loss of sense of humour, constant irritability with people, difficulty with making decisions, suppressed anger, difficulty in concentrating, the inability to finish one task before rushing on to the next, and so on. Many of these symptoms are the prelude to more serious illnesses, in which stress is one of the risk factors. Recent research has shown that the psycho–social or stress risk factors can be found in hypertension, chronic fatigue syndrome, coronary artery disease, mental disorders, and a range of other illnesses; also suppression of immune responses by the stress-related hormones may provide chemical explanations of links between environmental and emotional pressures and susceptibility to diseases.

Cary L. Cooper

Bibliography

Albrecht, K. (1979). Stress and the manager. Making it work for you. Prentice-Hall, New Jersey.
Cooper, C. (ed.) (1996). Handbook of stress, medicine and health. CRC Press, Boca Raton, Florida.
Hinkle, L. E. (1973). The concept of stress in the biological social sciences. Stress medicine and man 1, 31–48.
Lazarus, R. E. (1976). Patterns of adjustment. McGraw-Hill, New York.
Melhuish, A. (1978). Executive health. Business Books, London.

See also autonomic nervous system.