Updated: Jun 8, 2021
Hans Selye, a Hungarian-Canadian endocrinologist and known as the Father of Stress Theory, once said,
“Every stress leaves an indelible scar, and the organism pays for its survival after a stressful situation by becoming a little older."
Most of the time, you use the term “stress” to actually mean “stressors”. That is because, more often than not, you associate stress with undesirable situations.
One of the six areas of focus of Lifestyle Medicine is stress management. This article will discuss stress, how it affects you, and why Lifestyle Medicine focuses on stress management.
Good and Bad Stress
Any circumstance that causes you stress is called a stressor. It could be physical or physiological changes in the body, changes in the environment, life events, or behavioral changes. Even imaginary situations like worry and fear could become stressors.
However, stress is a normal physical and psychological reaction of your body to the demands of your daily life. A little amount of stress motivates you to perform better. Eustress or good stress does not only help you in restoring your energy but also improve your heart function and increase your stamina and strength. They sharpen your thinking and enhance your mental ability.
Distress on the other hand, has a negative impact on your body. It causes you anxiety or a feeling of displeasure. Distress affects your performance and can lead to your mental as well as physical problems.
With today’s modern living, stress becomes a double-edged sword that could kill you if left unmanaged over time. Hence, it is very important how you perceive an event or a situation because the way you handle stress is an indicator of your overall health and well-being.
The Physiology of Stress
General Adaptation Syndrome
In 1936, Hans Selye conducted a study on the hypothetical "non-specific response of the body to any demand". That was how Selye first describe "stress" in medical terms and the stress model General Adaptation Syndrome was conceived.
Selye theorized that the body adapts constantly to stressors in a predictable biological pattern so that the body's internal equilibrium or homeostasis would be restored and maintained. His study explains the stress response and how chronic exposure to stress can cause aging and diseases.
To understand how stress affects your body, Selye described the General Adaptation Syndrome into three stages:
The first step in a stress response is the perception of the threat or stressor --- real or imaginary. The hypothalamus in the brain perceives the stressor and performs the following:
Activates the Autonomic Nervous System (ANS)
The Autonomic Nervous System (ANS) regulates the activities of the internal organs like circulation, digestion, respiration, temperature regulation, excretion, etc. It consists of the sympathetic (arousal) and parasympathetic (relaxed) nervous system.
The sympathetic system is responsible for the fight-or-flight response. In response to a stressor, catecholamines --- epinephrine (adrenaline) and norepinephrine (noradrenaline) --- are released causing several changes like increase in your heart rate, increase in the force of heart contraction, vasodilation of arteries to the working muscles, vasoconstriction of arteries to non working muscles, dilation of pupil and bronchi, and reduction of digestive activities in the body. All these changes are required to prepare your body for fight-or-flight response which last for a few seconds.
2. Stimulates the Hypothalamic Pituitary Adrenal (HPA) axis by releasing Corticotropin Releasing Hormone (CRH)
Your pituitary gland controls the secretion of other hormones in the body. Upon stimulation of the CRH, your pituitary gland secretes Adrenocorticotropic Hormone (ACTH) which would stimulate the adrenal glands in the kidneys releasing glucocorticoids and mineralocorticoids.
Glucocorticoids release energy to cope with the ill-effects of stressors. The energy released converts glycogen into glucose and breaks down fats into fatty acids and glycerol. In addition, this corticoid also increases urea production, suppresses your appetite, suppresses your immune system, exacerbates your gastric irritation, contributes to your feeling depressed and loss of control. These are the symptoms generally seen in persons under stress.
Mineralocorticoids promotes sodium retention and elimination of potassium. This results in an increase of blood volume thus increasing blood pressure.
Also your adrenal gland secretes epinephrine (adrenaline) and norepinephrine (noradrenaline) as a backup system to ensure your physical survival as intermediate effects.
3. Secretes arginine vasopressin or Antidiuretic Hormone (ADH)
ADH is synthesized by your hypothalamus and released by your pituitary gland. It regulates fluid loss through your urinary tract by reabsorbing water in your body. Also, ADH has a role in regulating blood pressure during stress when your body's homeostasis is disturbed by the release of energy.
Another change occurring during stress is the distribution of energy to a particular organ that needs it most. This is achieved by increasing blood pressure. This occurs either through enhanced cardiac output or through constriction of the blood vessel.
Other hormones such as the growth and thyroid hormones also play a significant role in stress. Growth hormone raises the concentration of glucose and free fatty acids. It has been observed that in humans, psychological stimuli increase the concentration of thyroid hormones. Your thyroid gland releases thyroxine and triiodothyronine. These hormones also have some significant function in stress increasing your overall metabolic rate. Thyroxine also increases heart rate and sensitivity of some tissues to catecholamines.
Although serotonin and melatonin are not considered stress hormones, they are associated with mood which decrease during depression brought about by stress.
Adaptation or Resistance Stage
After the body has responded to the stressor, it is expected that the stress level has been reduced, if not eradicated. However, after your initial fight-or-flight response, your body’s defenses become weaker because your body allocates energy to repair the damaged tissues and to lower the production of the stress hormones.
Although your body has shifted to this phase of stress, it remains alert especially when the stressors persist and your body needs to fight them continuously. However, due to lower defenses, your body fights not as stronger as during the alarm stage.
If the stressful situation is not resolved, the body uses all its resources to adapt. This results in sleep problems, tiredness, muscle pains, indigestion, allergies, infections, common colds, lack of concentration, impatience, irritability, smoking and drinking.
Recovery or Exhaustion Stage
If your body’s compensatory mechanisms have succeeded in overcoming the stressor’s effects, recovery follows. But if your body has used up its resources and is unable to maintain normal function it leads to exhaustion.
During exhaustion, your body starts to lose its ability to combat the stressors because the adaptive energy is all drained out. The exhaustion stage can be the gateway towards burnout or stress overload, which can cause long term effects putting you at risk of suffering from more serious health conditions.
Impact of Stress to Your Body
Acute stress occurs for a short period of time. It comes on quickly and also goes quickly. Acute stress is generally recognized with symptoms such as anger, anxiety, irritability and acute periods of depression. Sometimes it may bring you thrill, pleasure and excitement.
When acute stress is felt too frequently it is called episodic stress. It occurs due to a series of stressful challenges occurring one after another in your life. Bills which do come frequently is an example of episodic stress.
When a stress persists for longer duration it is called chronic stress. It is brought about by your prolonged exposure to stressors. Chronic stressors may not be as intense as acute stressors but they are more harmful than acute stressors because the effect of chronic stress has accumulated for a long time.
Stress affects your body in many ways both physical as well as mental. The impact of stress on the body may not be the same in all people. It may vary depending on factors like the genotype, sex, age, physiological conditions and past experiences of the person. But some of these effects are common to every individual. Most of the effects are due to increased concentrations of corticoids and adrenaline.
Disturbed eating habits, acid reflux, diarrhea or constipation are the common symptoms seen in stressed persons. Stress can also be related to obesity which is linked to a host of other health problems. Hormonal changes occurring during the acute and chronic stress can affect glucose homeostasis in both healthy people and in those with diabetes.
Extreme stress can also be associated with diabetes because excessive cortisol can affect the insulin activity. The body can also become resistant to insulin which can lead to diabetes.
Several studies show a strong relationship between stress and cardiovascular diseases. Stress plays a role in susceptibility, progress and outcome of cardiovascular diseases. Psychological stresses are also associated with cardiovascular diseases because it has become psychosomatic.
Increased adrenaline and cortisol during stress affect your heart and blood pressure. Too much adrenaline causes your blood pressure to elevate making your heart pump harder and faster. This action can result to heart disease, stroke, or cardiac arrest. Stress has been reported to be an indicator of coronary heart disease and hypertension.
Chronic stress also leads to increased blood cholesterol levels. The persistent high levels of cho