Stress

Stress

by Ingrid M. Cordon

(spring 1997)

At one time or another, most people experience stress. The term stress has been used to describe a variety of negative feelings and reactions that accompany threatening or challenging situations. However, not all stress reactions are negative. A certain amount of stress is actually necessary for survival. For example, birth is one of the most stressful experiences of life. The high level of hormones released during birth, which are also involved in the stress response, are believed to prepare the newborn infant for adaptation to the challenges of life outside the womb. These biological responses to stress make the newborn more alert promoting the bonding process and, by extension, the child's physical survival. The stress reaction maximizes the expenditure of energy which helps prepare the body to meet a threatening or challenging situation and the individual tends to mobilize a great deal of effort in order to deal with the event. Both the sympathetic/adrenal and pituitary/adrenal systems become activated in response to stress. The sympathetic system is a fast-acting system that allows us to respond to the immediate demands of the situation by activating and increasing arousal. The pituitary/adrenal system is slower-acting and prolongs the aroused state. However, while a certain amount of stress is necessary for survival, prolonged stress can affect health adversely (Bernard & Krupat, 1994).

Stress has generally been viewed as a set of neurological and physiological reactions that serves an adaptive function (Franken, 1994). Traditionally, stress research has been oriented toward studies involving the body's reaction to stress and the cognitive processes that influence the perception of stress. However, social perspectives of the stress response have noted that different people experiencing similar life conditions are not necessarily affected in the same manner (Pearlin, 1982). Research into the societal and cultural influences of stress may make it necessary to re-examine how stress is defined and studied.

There are a number of definitions of stress as well as number of events that can lead to the experience of stress. People say they are stressed when they take an examination, when having to deal with a frustrating work situation, or when experiencing relationship difficulties. Stressful situations can be viewed as harmful, as threatening, or as challenging. With so many factors that can contribute to stress it can be difficult to define the concept of "stress". Hans Selye (1982) points out that few people define the concept of stress in the same way or even bother to attempt a clear-cut definition. According to Selye, an important aspect of stress is that a wide variety of dissimilar situations are capable of producing the stress response such as fatigue, effort, pain, fear, and even success. This has led to several definitions of stress, each of which highlights different aspects of stress. One of the most comprehensive models of stress is the Biopsychosocial Model of Stress (Bernard & Krupat, 1994). According to the Biopsychosocial Model of Stress, stress involves three components: an external component, an internal component, and the interaction between the external and internal components.

The external component of the Biopsychosocial Model of stress involves environmental events that precede the recognition of stress and can elicit a stress response. A previously mentioned, the stress reaction is elicited by a wide variety of psychosocial stimuli that are either physiologically or emotionally threatening and disrupt the body's homeostasis (Cannon, 1932). We are usually aware of stressors when we feel conflicted, frustrated, or pressured. Most of the common stressors fall within four broad categories: personal, social/familial, work, and the environment. These stressful events have been linked to a variety of psychological physical complaints. For example bereavement is a particularly difficult stressor and has provided some of the first systematic evidence of a link between stress and immune functioning. Bereavement research generally supports a relationship between a sense of loss and lowered immune system functioning. Health problems and increased accidents are also associated with stressful work demands, job insecurity and changes in job responsibilities (Bernard & Krupat, 1994). Stressors also differ in their duration. Acute stressors are stressors of relatively short duration and are generally not considered to be a health risk because they are limited by time. Chronic stressors are of relatively longer duration and can pose a serious health risk due to their prolonged activation of the body's stress response.

The internal component of stress involves a set of neurological and physiological reactions to stress. Hans Selye (1985) defined stress as "nonspecific" in that the stress response can result from a variety of different kinds of stressors and he thus focused on the internal aspects of stress. Selye noted that a person who is subjected to prolonged stress goes through three phases: Alarm Reaction, Stage of Resistance and Exhaustion. He termed this set of responses as the General Adaptation Syndrome (GAS). This general reaction to stress is viewed as a set of reactions that mobilize the organism's resources to deal with an impending threat. The Alarm Reaction is equivalent to the fight-or-flight response and includes the various neurological and physiological responses when confronted with a stressor. When a threat is perceived the hypothalamus signals both the sympathetic nervous system and the pituitary. The sympathetic nervous system stimulates the adrenal glands. The adrenal glands release corticosteroids to increase metabolism which provides immediate energy. The pituitary gland releases adrenocorticotrophic hormone (ACTH) which also affects the adrenal glands. The adrenal glands then release epinephrine and norepinephrine which prolongs the fight-or-flight response. The Stage of Resistance is a continued state of arousal. If the stressful situation is prolonged, the high level of hormones during the resistance phase may upset homeostasis and harm internal organs leaving the organism vulnerable to disease. There is evidence from animal research that the adrenal glands actually increase in size during the resistance stage which may reflect the prolonged activity. The Exhaustion stage occurs after prolonged resistance. During this stage, the body's energy reserves are finally exhausted and breakdown occurs. Selye has noted that, in humans, many of the diseases precipitated or caused by stress occur in the resistance stage and he refers to these as "diseases of adaptation." These diseases of