In order to develop a general theory for the physiological response of humans and animals to stress, Hans Selye, former director of Experimental Medicine and Surgery at the University of Montreal, performed an integrated analysis of the effects of stress on adrenal gland function. He called his model of stress adaptation the General Adaptation Syndrome or GAS.
The GAS was thought by Selye to outline how the organism adapts physiologically to stressors in its attempt to restore homeostasis. The GAS has proven useful for many years by providing a model of how stress-induced illness arises and by giving clinicians some insight into how to manage stress related conditions in their patients. According to Selye, there are three stages of stress response: alarm phase (acute stress); resistance phase (chronic stress); and exhaustion phase (burnout).Stress includes not only psychological stress but also any insult to the body that may tax the adrenal gland function, including chronic infections, allergies, exposure to chemical toxins, use of stimulants (such as caffeine and nicotine), poor nutrition, physical trauma, and poor sleep habits, Other contributing factors include exogenous steroid use, chronic hypoglycemia, and pharmaceutical and non-pharmaceutical drug use. For instance, many people develop adrenal exhaustion after a physical trauma, such as a car accident, after an acute exposure to toxins in the workplace, or after an extended course of corticosteroid treatment.Alarm Phase (Acute Stress) The alarm phase of the GAS occurs when a stress is first encountered and an alarm is sounded in the body.
This alarm, sometimes called the fight or flight response, is associated with an activation of the sympathetic nervous system. Hormonally, we see an increase in the release of cortisol from the adrenal cortex and epinephrine from the adrenal medulla. This response is a normal defense mechanism that engages when an organism is threatened, and serves a critical function by stimulating the organism to respond to the threat at hand.Once this phase is over, the body goes through a 24 to 48 hour period of recovery, during which one desires primarily to rest. However, this response can be considered maladaptive when the hormonal release is not appropriate for the situation (e. g.
, in states of hyper-vigilance, chronic anxiety syndromes, post-traumatic stress disorder). Animal studies of prolonged alarm reactions associate this stage with weight loss, gastric ulcers, and immunosuppression. Resistance Phase (Chronic Stress) Due to the challenges of modern life, for many people the perceived stressors are not short term but chronic.In this second phase of the GAS, the organism is still reacting to a perceived stress or stresses, but some of the outwardly observable signs of stress are different. Levels of cortisol and epinephrine are still elevated.
This chronic elevation results in weight gain, although the person may appear to have returned to normal functioning. However, immunity and inflammatory responses are still suppressed, and thus there is an increased susceptibility to opportunistic infections, neoplasia, arthritis, allergies, and autoimmune conditions.In addition, chronically elevated adrenal hormone levels may lead to depression, hyperlipidemia, atherosclerosis, hypertension, hyperinsulinemia, insulin resistance, diabetes, osteoporosis, and other degenerative diseases. Exhaustion Phase (Burnout) No matter how vital the person, chronic stress can eventually lead to the exhaustion phase, characterized by a deficient production of glucocorticoids and an episodic increase in epinephrine. This phase is associated with deficient glucocorticoid and mineralocorticoid production, sometimes combined with episodic pulses of excess epinephrine.This is commonly known as adrenal exhaustion.
Adrenal exhaustion is associated with decreased resistance to stress, premature aging, and, if left uncorrected, even death. Conditions that are common in people in this phase of the GAS include allergies, chronic fatigue syndrome, fibromyalgia, hypoglycemia, multiple chemical sensitivities, irritable bowel syndrome, hypotension, insomnia, hypothyroid, lack of motivation, Addison’s disease is a failure of the adrenal cortex.It affects approximately four people in 100,000 and occurs n all age groups and among both sexes equally. Addison’s disease can be triggered by acute external stressors, such as infection, trauma, toxic chemical exposure, corticosteroid withdrawal, or extreme psychological stress. 3 It is considered to be autoimmune in nature, and can affect other glands, including the thyroid and pituitary.
Symptoms Symptoms include hyperpigmentation (mouth, areolae, perineum), weight loss, asthenia, depression, and postural hypotension causing vertigo.Extreme adrenal crisis can lead to vascular collapse with hypotension and azotemia. Tests Conventional tests to detect Addison’s include serum cortisol, 24-hour free cortisol, and the ACTH stimulation test. Standard electrolytes may be imbalanced with an elevation of serum potassium and depression of serum sodium. Adrenal Insufficiency Syndrome Adrenal insufficiency is common in Western culture due to the high amount of psychological stress, environmental toxins, and poor nutrition, all of which deplete adrenal reserves.Other lifestyle factors in adrenal insufficiency development include inadequate amount of sleep, eating infrequently, and lack of exercise.
Adrenal insufficiency can be thought of as an acute or chronic impairment of adrenal function, as opposed to the failure of the gland, as seen in Addison’s disease. Therefore, it may be more difficult to diagnose adrenal insufficiency than Addison’s disease. Symptoms are an important consideration, as first identified by Dr John Tintera in 1956.
