Although philosophers and physicians have been aware of the trials and tribulations of life for centuries, the recognition of stress as a definable force in human health and well-being grew out of research begun in the 1930s. Nineteenth century physiologists such as C. Bernard pointed out that any living organism-human beings included-had internal environments that needed to be maintained in some stable state despite changes in the world around it. In other words, the organism had to adapt or compensate in response to disturbances of its internal balance. The twentieth century physiologist W. B. Cannon suggested the term ''homeostasis'' to refer to this need of the organism to maintain a balanced state in order to survive. (For further exploration of Cannon' s work, please refer to The Wisdom of the Body, 1939.)

The Work of Hans Selye
      In the 1930s, Hans Selye began his ground-breaking work exploring the body's reaction to external stimuli, such as cold, infection, or a variety of events. He identified the body's reaction as the General Adaptation Syndrome [GAS]. To Selye, stress was a nonspecific adaptive response of the body to an environmental or emotional demand placed upon it.  

      According to Selye, the human organism responds to stress in a reasonably predictable pattern, involving three stages:

1.	An alarm reaction, or initial response involving a cascade of hormonal and biochemical processes which prepare the body for "fight or flight";
2.	A stage of resistance, with its own set of biochemical events; and
3.	A stage of exhaustion which occurs if the demand placed upon the human organism continues for too long, or if the demand is too severe.

      It is important to realize that not all stress is bad. In fact, Selye developed the term "eustress"  in 1974 to identify the positive type of stress that motivates a person to attain goals without causing physical damage. Thousands of years ago, the General Adaptation Syndrome would have been highly beneficial for human survival.

A Story of the Stress Reaction
      For example, imagine 'lJfimitive" man walking through the grasslands one morning, and encountering a tiger. He has three choices at this point. He can

If he does not wish to be the lunch for the tiger, his body must undergo some massive reactions in a very short time: his heart rate increases, his blood sugar rises to provide energy, he breathes faster, his muscles tense up, and he is ready to fight or flee. In case things go badly, his blood becomes more prepared to clot to prevent serious bleeding if injured.

(Please refer to the schematic diagram for an illustration of the various mechanisms which cause these symptoms.)

      Once the situation resolves, the biochemical factory returns to normal production levels and the body restores its normal state, or homeostasis. The body has successfully adapted to a stressor (the tiger), and then it returns to normal (we hope!). It is unlikely that the modem man or woman will run into a tiger on the way to work, but he or she does run into a traffic jam, a computer failure, or a critical boss. The eyes may be looking at the boss, the brain may recognize the boss, but the body says "TIGER!" So the body responds accordingly. Now it is generally not a good idea to physically fight with the boss, and it is not always possible to escape; but the body still turns into a magnificent biochemical factory operating at wartime production levels-creating the familiar palpitations, stiff neck, headache, and other symptoms that we've come to recognize as stress symptoms.

      Selye's work describing the GAS was invaluable because it proved what a profound effect physical or emotional demands could have on the body. It is important to note that Selye' s three stage model may not always apply in all cases, particularly in cases of chronic stress. 

      If the body reacted to prolonged stressful situations with the same intensity as it deals with acute stress, it would not be able to function for long. To quote Jeanne A chterberg, "the body has primed itself for a war that may never happen, and therefore the state of readiness must dissipate rapidly or else become the enemy within" [ Imagery in Healing: Shamanism and Modern Medicine , (Boston: Shambala Publications, 1985). This is considered to be the root of conditions such as migraine headaches and high blood pressure; the body holds onto the effects of emergency stress, or the "fight or flight" response, too long. What worked well in a short-term setting ages ago can now prove harmful to the body.

      In most cases, if a person is exposed to long periods of stress, the body's mechanisms will change. The major result will be excessive secretion of adrenal hormones, such as the gluocorticoids (e.g., hydrocortisone) and the pituitary gland hormone ACTH.. The long term result of this overproduction is reduction in the body's ability to defend itself The immune system becomes less effective, as we shall discuss later.

      Whether acute or chronic, stress-according to Selye' s model-triggers a dramatic physiological response. While the short-term effects may be very helpful, such as being able to escape from the tiger, the long-term effects can be damaging to the body.

      Selye's definition of stress was as a response, implying that the human being is reacting to something rather than interacting with it. But stress is more than a response, as we shall see later.

Controversy and Discussion
      There has been considerable controversy over the exact definition of the word "stress." In the physical sciences, stress has commonly been thought of as a force acting upon the organism-a stimulus from the external or internal human environment. In psychology, the definition of stress has also taken on a more interactive connotation, looking at the myriad variables which determine how a person reacts to a stimulus. Sociological definitions of stress have placed more attention on the ways in which social resources can mitigate the effects of stressful situations, whether acute or chronic.

      Along with Selye, one of the leading figures in the literature about stress is Richard Lazarus. Lazarus and his colleagues looked at stress from a relational perspective, exploring how the person relates to and interacts with the environmental or emotional stimuli. The person appraises each encounter, and identifies whether that encounter is threatening. How the person appraises the situation will, in turn, be affected by many variables, including prior experiences, beliefs about the self or environment, what resources are available, etc. Lazarus and Kenneth A. Holroyd advocate "discarding stimulus and response conceptions of stress in favor of relational formulations that do not artificially isolate the personal and environmental determinants of the stress experience" [Kenneth A. Holroyd and Richard S. Lazarus, "Stress, Coping, and Somatic Adaptation," in Handbook of Stress: Theoretical and Clinical Aspects . Leo Goldberger and Shlomo Brenitz, eds. (New York: The Free Press, 1982),].

      Although more recent research tends to favor the interactive elements proposed by Lazarus et at, no one theory seems to address the topic in a comprehensive fashion. To quote physician John Mason, "whatever the soundness of logic may be in the various approaches to defining 'stress,' the general picture in the field can still only be described as one of confusion. " ["A Historical View of the Stress Field," Journal of Human Stress . June 1975: 1 (2), p.28.]

New Ideas
      For this book, we have developed a new model for explaining what stress is. This model incorporates recent developments in science and philosophy. 

      Revolutions in physics and sciences, such as the development and popularization of quantum theories, have forced us to create a new view of ourselves and our reality. This new vision turns away from the mechanistic world view to one where matter and life are interconnected.

This world view of modem physics is a systems view....based on awareness of the essential interrelatedness and interdependence of all phenomena-physical, biological, psychological, social, and cultural. (Fritjof Capra. The Turning Point: Science , Society, and the Rising Culture. (Toronto: Bantam Books, 1982)

      Within this conceptual framework, the mind is seen as being immanent in the body -''the' command center' so to speak: a multilevel and integrated pattern of processes that represent the dynamics of human self-organization." [Capra] 

      Nineteenth century science operated within a linear framework: if A happens to Organism X, B will follow. Selye, incorporated this idea into his description of the General Adaptation Syndrome: if stimulus A is presented to a person, physiological responses B-Q will result. Lazarus modified this sequence by looking at the organism's interaction with its environment, although he did not tie this concept in with systems theory per se.

How would Capra define stress? From a systems perspective, stress is an imbalance that occurs within the organism in response to something in the environment. The organism is pushed to its extremes, thereby llnp airing its ability to adapt and be flexible. This increased rigidity can then potentially contribute to the development of physical and psychological disease or illness.

      Going beyond the ideas of systems theory, recent developments in the branch of study known as chaos theory provide key insights into our definition of stress. Chaos theory looks at behaviors and patterns within complex systems. What is revealed is chaos: complex systems are in constant motion, interacting with environmental stimuli and exhibiting unpredictable behaviors. In essence, behavior of all entities-including living organisms-functions in a non-linear manner. Behavior is not totally predictable.

Human beings operate in a non-linear fashion; each individual has his or her own patterns, or unique ways of reacting to any given stimulus. We do not react to a given stressor in a predictable way; we do not follow linear patterns-we do not follow a straight line throughout our lives. An encounter which causes me great stress today may not affect me next week.

It is from this perspective, fusing the wisdom of new scientific knowledge with a holistic perspective of the human organism, that I propose a new way oflookllg at and managing stress. My definition of stress is a body-mind-spirit reaction which a human being experiences when exposed to any event which that person at that moment views as threatening to his or her state of security or balance . It is a highly subjective experience that varies for each person.

      For example, returning to the story of our ancestor and the tiger, that tiger was a very real threat to the man's physical safety-his security, his sense of mental and physical balance was in jeopardy. One could expect that he experienced stress. He experienced all the biochemical and physical signs and symptoms which Selye described. A more modem example would be the morning commute. If I'm in a hurry to get to work, being stuck in traffic is stressful-my heart pounds, my muscles tighten, and I feel tense. If I'm not going anywhere at a particular time, traffic might not be such a trigger.

Stress can also result from any change in one's life-good or bad. Change demands us to adapt, to alter our way of being in some fashion. Any change can be stressful.

Challenges to a person's sense of self-confidence can also cause stress. Any Performer knows that walking on stage triggers a variety of physical and emotional reactions quite consistent with Selye' s description of the GAS: the heart pounds, the blood pressure rises, the muscles tense, and so on. While his or her physical security is not usually at risk, the ability to cope or to deliver what is expected is definitely challenged.

An often overlooked source of stress is when a person is not receiving something that he needs. Obviously, a lack of food or shelter is clearly a cause of stress. But so is an unmet need for love, for approval for power, for self-development. A working mother may experience stress from a variety of causes: unmet needs for time for herself: unmet needs for appreciation at work, threats to her concept of herself as a good mother, or the very real stress of lack of sleep. 

As you can see, each of us will experience stress from any number of causes. How we react will vary from moment to moment, day to day. We are constantly changing and growing, and we look at the world around us through a new lens each morning.

As Lazarus and his colleagues showed, each person interacts with and interprets incoming stimuli, thereby determining how he will react. He determines if the stimulus is a stressor or not. A human being is an open system interacting with both the internal and external environments: the body, the mind, the spirit, and the psyche all merge and intersect as part of an overall galaxy.

MIND BODY SPIRIT - PSYCHE

      The concept of natural systems gives us a model to see just how interconnected the mind and the body really are. Natural structures, including human beings, are psychobiological unities in which there is a constant flow information from one part of the body to the other and back again. It is from this perspective, along with other new evidence from the field of psychoneuroimmunology which helps to demonstrate that a person's emotional state can have a dramatic impact on his physical state of health-including contributing to the development of ilIness.

      The next step in our exploration process is to discuss how stress can impact each of the major body systems, and the connections between stress and illness. It is again important to state that each person is unique, and responds differently to stressful situations at different times in his life.

      We have all heard our mends, our co-workers, and probably ourselves complain of ' tension headaches,' 'stress ulcers,' or a variety of other conditions that can be stress related. To learn how to manage stress effectively, we need to understand the mechanisms underlying these processes and reactions. Recent research has provided considerable insight into how stress causes illness, expanding from the base of information begun by Selye.

      Although it is most common to read about the connection between stress and the development of cardiovascular disease, we'll begin our study with the area of research that is revolutionizing the way we look at ourselves and our health: the link between stress, the brain, and the immune system

STRESS   THE BRAIN THE IMMUNE SYSTEM