Stress, The Invisible killer
Stress is a term in psychology and biology,
borrowed from physics and engineering and first used in the biological
context in the 1930s, which has in more recent decades become commonly
used in popular parlance. It refers to the consequence of the failure of an organism – human or animal – to respond adequately to mental, emotional or physical demands, whether actual or imagined.
Signs of stress may be cognitive, emotional, physical or behavioral. Signs include poor judgment, a general negative outlook, excessive worrying, moodiness, irritability, agitation, inability to relax, feeling lonely, isolated or depressed, aches and pains, diarrhea or constipation, nausea, dizziness, chest pain, rapid heartbeat, eating too much or not enough, sleeping too much or not enough, social withdrawal, procrastination or neglect of responsibilities, increased alcohol, nicotine or drug consumption, and nervous habits such as pacing about, nail-biting and neck pains.
Physiologists define stress as how the body reacts to a stressor, real or imagined, a stimulus that causes stress. Acute stressors affect an organism in the short term; chronic stressors over the longer term.
Selye researched the effects of stress.
Alarm is the first stage. When the threat or stressor is identified or realized, the body's stress response is a state of alarm. During this stage adrenaline will be produced in order to bring about the fight-or-flight response. There is also some activation of the HPA axis, producing cortisol.
Resistance is the second stage. If the stressor persists, it becomes necessary to attempt some means of coping with the stress. Although the body begins to try to adapt to the strains or demands of the environment, the body cannot keep this up indefinitely, so its resources are gradually depleted.
Exhaustion is the third and final stage in the GAS model. At this point, all of the body's resources are eventually depleted and the body is unable to maintain normal function. The initial autonomic nervous system symptoms may reappear (sweating, raised heart rate etc.). If stage three is extended, long term damage may result as the body, and the immune system is exhausted and function is impaired resulting in decompensation.
The result can manifest itself in obvious illnesses such as ulcers, depression, diabetes, trouble with the digestive system or even cardiovascular problems, along with other mental illnesses.
Selye published in 1975 a model dividing stress into eustress and distress. Where stress enhances function (physical or mental, such as through strength training or challenging work) it may be considered eustress. Persistent stress that is not resolved through coping or adaptation, deemed distress, may lead to anxiety or withdrawal (depression) behavior.
The difference between experiences which result in eustress or distress is determined by the disparity between an experience (real or imagined), personal expectations, and resources to cope with the stress. Alarming experiences, either real or imagined, can trigger a stress response.
Lazarus argued that in order for a psychosocial situation to be stressful, it must be appraised as such. He argued that cognitive processes of appraisal are central in determining whether a situation is potentially threatening, constitutes a harm/loss, a challenge, or is benign.
Both personal and environmental factors influence this primary appraisal, which then triggers the selection of coping processes. Problem-focused coping is directed at managing the problem, while emotion-focused coping processes are directed at managing the negative emotions. Secondary appraisal refers to the evaluation of the resources available to cope with the problem, and may alter the primary appraisal.
In other words, primary appraisal includes the perception of how stressful the problem is and the seconday appraisal of estimating whether one has more than or less than adequate resources to deal with the problem which affects the overall appraisal of stressfulness. Further, coping is flexible in that the individual generally examines the effectiveness of the coping on the situation; if it is not having the desired effect, s/he will generally try different strategies.
Although the basic neurochemistry of the stress response is now well understood, much remains to be discovered about how the components of this system interact with one another, in the brain and throughout the body. In response to a stressor, neurons with cell bodies in the paraventricular nuclei (PVN) of the hypothalamus secrete corticotropin-releasing hormone (CRH) and arginine-vasopressin (AVP) into the hypophyseal portal system.
The locus ceruleus and other noradrenergic cell groups of the adrenal medulla and pons, collectively known as the LC/NE system, also become active and use brain epinephrine to execute autonomic and neuroendocrine responses, serving as a global alarm system.
The autonomic nervous system provides the rapid response to stress commonly known as the fight-or-flight response, engaging the sympathetic nervous system and withdrawing the parasympathetic nervous system, thereby enacting cardiovascular, respiratory, gastrointestinal, renal, and endocrine changes. The HPA axis, a major part of the neuroendocrine system involving the interactions of the hypothalamus, the pituitary gland, and the adrenal glands, is also activated by release of CRH and AVP.
This results in release of adrenocorticotropic hormone (ACTH) from the pituitary into the general bloodstream, which results in secretion of cortisol and other glucocorticoids from the adrenal cortex. The related compound, cortisone, is frequently used as a key anti-inflammatory component in drugs that treat skin rashes and in nasal sprays that treat asthma and sinusitis. Recently, scientists realized the brain also uses cortisol to suppress the immune system and reduce inflammation within the body. These corticoids involve the whole body in the organism's response to stress and ultimately contribute to the termination of the response via inhibitory feedback.
Chronic stress can significantly affect many of the body's immune systems, as can an individual's perceptions of, and reactions to, stress. The term psychoneuroimmunology is used to describe the interactions between the mental state, nervous and immune systems, as well as research on the interconnections of these systems. Immune system changes can create more vulnerability to infection, and have been observed to increase the potential for an outbreak of psoriasis for people with that skin disorder.
Chronic stress has also been shown to impair developmental growth in children by lowering the pituitary gland's production of growth hormone, as in children associated with a home environment involving serious marital discord, alcoholism, or child abuse.
Chronic stress is seen to affect parts of the brain where memories are processed through and stored. When people feel stressed, stress hormones get over-secreted which affects the brain. This secretion is made up of glucocorticoids, also known as cortisol, which are steroid hormones that the adrenal gland releases.
Studies of female monkeys at Wake Forest University (2009) discovered that individuals suffering from higher stress have higher levels of visceral fat in their bodies. This suggests a possible cause-and-effect link between the two, wherein stress promotes the accumulation of visceral fat, which in turn causes hormonal and metabolic changes that contribute to heart disease and other health problems.
Signs of stress may be cognitive, emotional, physical or behavioral. Signs include poor judgment, a general negative outlook, excessive worrying, moodiness, irritability, agitation, inability to relax, feeling lonely, isolated or depressed, aches and pains, diarrhea or constipation, nausea, dizziness, chest pain, rapid heartbeat, eating too much or not enough, sleeping too much or not enough, social withdrawal, procrastination or neglect of responsibilities, increased alcohol, nicotine or drug consumption, and nervous habits such as pacing about, nail-biting and neck pains.
Physiologists define stress as how the body reacts to a stressor, real or imagined, a stimulus that causes stress. Acute stressors affect an organism in the short term; chronic stressors over the longer term.
Selye researched the effects of stress.
Alarm is the first stage. When the threat or stressor is identified or realized, the body's stress response is a state of alarm. During this stage adrenaline will be produced in order to bring about the fight-or-flight response. There is also some activation of the HPA axis, producing cortisol.
Resistance is the second stage. If the stressor persists, it becomes necessary to attempt some means of coping with the stress. Although the body begins to try to adapt to the strains or demands of the environment, the body cannot keep this up indefinitely, so its resources are gradually depleted.
Exhaustion is the third and final stage in the GAS model. At this point, all of the body's resources are eventually depleted and the body is unable to maintain normal function. The initial autonomic nervous system symptoms may reappear (sweating, raised heart rate etc.). If stage three is extended, long term damage may result as the body, and the immune system is exhausted and function is impaired resulting in decompensation.
The result can manifest itself in obvious illnesses such as ulcers, depression, diabetes, trouble with the digestive system or even cardiovascular problems, along with other mental illnesses.
Selye published in 1975 a model dividing stress into eustress and distress. Where stress enhances function (physical or mental, such as through strength training or challenging work) it may be considered eustress. Persistent stress that is not resolved through coping or adaptation, deemed distress, may lead to anxiety or withdrawal (depression) behavior.
The difference between experiences which result in eustress or distress is determined by the disparity between an experience (real or imagined), personal expectations, and resources to cope with the stress. Alarming experiences, either real or imagined, can trigger a stress response.
Lazarus argued that in order for a psychosocial situation to be stressful, it must be appraised as such. He argued that cognitive processes of appraisal are central in determining whether a situation is potentially threatening, constitutes a harm/loss, a challenge, or is benign.
Both personal and environmental factors influence this primary appraisal, which then triggers the selection of coping processes. Problem-focused coping is directed at managing the problem, while emotion-focused coping processes are directed at managing the negative emotions. Secondary appraisal refers to the evaluation of the resources available to cope with the problem, and may alter the primary appraisal.
In other words, primary appraisal includes the perception of how stressful the problem is and the seconday appraisal of estimating whether one has more than or less than adequate resources to deal with the problem which affects the overall appraisal of stressfulness. Further, coping is flexible in that the individual generally examines the effectiveness of the coping on the situation; if it is not having the desired effect, s/he will generally try different strategies.
Although the basic neurochemistry of the stress response is now well understood, much remains to be discovered about how the components of this system interact with one another, in the brain and throughout the body. In response to a stressor, neurons with cell bodies in the paraventricular nuclei (PVN) of the hypothalamus secrete corticotropin-releasing hormone (CRH) and arginine-vasopressin (AVP) into the hypophyseal portal system.
The locus ceruleus and other noradrenergic cell groups of the adrenal medulla and pons, collectively known as the LC/NE system, also become active and use brain epinephrine to execute autonomic and neuroendocrine responses, serving as a global alarm system.
The autonomic nervous system provides the rapid response to stress commonly known as the fight-or-flight response, engaging the sympathetic nervous system and withdrawing the parasympathetic nervous system, thereby enacting cardiovascular, respiratory, gastrointestinal, renal, and endocrine changes. The HPA axis, a major part of the neuroendocrine system involving the interactions of the hypothalamus, the pituitary gland, and the adrenal glands, is also activated by release of CRH and AVP.
This results in release of adrenocorticotropic hormone (ACTH) from the pituitary into the general bloodstream, which results in secretion of cortisol and other glucocorticoids from the adrenal cortex. The related compound, cortisone, is frequently used as a key anti-inflammatory component in drugs that treat skin rashes and in nasal sprays that treat asthma and sinusitis. Recently, scientists realized the brain also uses cortisol to suppress the immune system and reduce inflammation within the body. These corticoids involve the whole body in the organism's response to stress and ultimately contribute to the termination of the response via inhibitory feedback.
Chronic stress can significantly affect many of the body's immune systems, as can an individual's perceptions of, and reactions to, stress. The term psychoneuroimmunology is used to describe the interactions between the mental state, nervous and immune systems, as well as research on the interconnections of these systems. Immune system changes can create more vulnerability to infection, and have been observed to increase the potential for an outbreak of psoriasis for people with that skin disorder.
Chronic stress has also been shown to impair developmental growth in children by lowering the pituitary gland's production of growth hormone, as in children associated with a home environment involving serious marital discord, alcoholism, or child abuse.
Chronic stress is seen to affect parts of the brain where memories are processed through and stored. When people feel stressed, stress hormones get over-secreted which affects the brain. This secretion is made up of glucocorticoids, also known as cortisol, which are steroid hormones that the adrenal gland releases.
Studies of female monkeys at Wake Forest University (2009) discovered that individuals suffering from higher stress have higher levels of visceral fat in their bodies. This suggests a possible cause-and-effect link between the two, wherein stress promotes the accumulation of visceral fat, which in turn causes hormonal and metabolic changes that contribute to heart disease and other health problems.