Stress : Part 2 - The Drama

Like I mentioned earlier, the stress response creates some changes in your body in order to prepare you for ‘fight or flight’.

The hormones released during speed up heart rate, breathing rate (more oxygen), blood pressure, and metabolism.

Blood vessels open wider to let more blood flow to large muscle groups, putting our muscles on alert. Also, increases blood supply to your brain, lungs and heart.

Pupils dilate to improve vision.

The liver releases some of its stored glucose to increase the body's energy.

And sweat is produced to cool the body.

Spleen discharges more RBCs and WBCs into your blood stream which helps increase the oxygen carrying capacity and the ability to fight infections.

Fluid is diverted from non-essential sites (like the mouth). This can result in dry mouth and difficulty in speech. You can also have spasm of your throat muscles – causing difficulty in swallowing.

Blood flow is diverted from the skin to support your heart and muscles. This can result in cold, clammy and sweaty skin. It also reduces blood loss, in case you get a cut or injury during an attack (the blood also becomes stickier for the same reason). The scalp (and also tiny muscles in your skin) tend to tighten and makes it seem that your hair is standing up.

Your digestive system usually shuts down at such a time.

These are the acute changes that take place in your body, in response to acute stress.

Stress plays a significant role in presentation and progress of other health conditions..

~ Sudden stress increases the pumping action and rate of the heart and causes the arteries to constrict, thereby posing a risk for blocking blood flow to the heart.

~ Emotional effects of stress alter the heart rhythms and pose a risk for serious arrythmias in people with existing heart rhythm disturbances.

~ Stress causes blood to become stickier, increasing the likelihood of an artery-clogging blood clot.

~ Stress may signal the body to release fat into the bloodstream, raising blood-cholesterol levels.

Here is what can happen in chronic stress, when you are exposed to stress over long periods of time..

* In women, chronic stress may reduce estrogen levels, which are important for cardiac health.

* Stressful events may cause men and women who have relatively low levels of the neurotransmitter serotonin (and therefore a higher risk for depression or anger) to produce more cytokines, which in high amounts cause inflammation and damage to cells.

* Recent evidence confirms the association between stress and hypertension (high blood pressure). People who regularly experience sudden increases in blood pressure caused by mental stress may, over time, develop injuries in the inner lining of their blood vessels.

* People who are trying to deal with stress often resort to unhealthy habits including high-fat and high-salt diets, tobacco use, alcohol abuse, and a sedentary lifestyle.

* Chronic stress appears to blunt the immune response and increase the risk for infections and may even impair a person's response to immunizations.

* Prolonged stress can disrupt the digestive system, irritating the large intestine and causing diarrhea, constipation, cramping, and bloating. Excessive production of digestive acids in the stomach may cause a painful burning.

* Irritable bowel syndrome (or spastic colon) is strongly related to stress. The large intestine becomes irritated, and its muscular contractions are spastic rather than smooth and wave like. The patient has bloating, cramping and alternating periods of constipation and diarrhea.

* Stress may predispose someone to peptic ulcers or sustain existing ulcers.

* Often stress is related to weight gain and obesity. Many people develop cravings for salt, fat, and sugar to counteract tension and, thus, gain weight (which predisposes to diabetes and heart problems).

* Some people suffer a loss of appetite and lose weight. In rare cases, stress may trigger hyperactivity of the thyroid gland, stimulating appetite but causing the body to burn up calories at a faster than normal rate.

* Anorexia nervosa and bulimia nervosa are eating disorders that are highly associated with adjustment problems in response to stress and emotional issues.

* Chronic stress has been associated with the development of insulin-resistance, a condition in which the body is unable to use insulin effectively to regulate glucose (blood sugar).

* Chronic stress is found to be associated to joint and muscle pain (most common complaint is back pain).

* Tension-type headache episodes are highly associated with stress and stressful events.

* Among the wide range of possible migraine triggers is emotional stress.

* The tensions of unresolved stress frequently cause insomnia (can occur due to both acute and chronic stress).

* Stress can lead to diminished sexual desire and an inability to achieve orgasm in women. Stress response can also cause temporary impotence in men.

* Stress may even affect fertility. Stress hormones have an impact on the hypothalamus gland, which produces reproductive hormones. Severely elevated cortisol levels can even shut down menstruation.

* Maternal stress during pregnancy has been linked to a 50% higher risk for miscarriage. It is also associated with lower birth weights and increased incidence of premature births - infant mortality. Stress may cause physiologic alterations, such as increased adrenal hormone levels or resistance in the arteries, that may interfere with normal blood flow to the placenta.

* Studies indicate that the immediate effect of acute stress impairs short-term memory, particularly verbal memory.

* Studies have strongly associated chronic stress to shrinkage in the hippocampus, the center of memory.

* Unexplained Hair Loss (Alopecia Areata) is hair loss that occurs in localized (or discrete) patches and has been associated with stress.

There can be plenty more conditions which can be similarly associated.

Stress : Part 1 - The Culprits

Stress basically refers to the changes in the body which prepares itself to react to certain cirumstances. It is also referred to as the "fight or flight response". It is termed so, because the reaction of the body prepares you to either fight the stimulus (that caused the stress), or flee from it before it can cause any harm. (This theory is from an example of a person under attack by an animal - like a bear)

Stimuli which cause stress are reffered to as stressors. Stressors can be external (traumatic or psychological) or they may be internal (infections or inflammations). Stress can be classified as Acute (short-term or fight-flight response) or Chronic (long-term) stress. After an acute stress response, the body changes reverse and returns to normal (relaxation response). Chronic stress is a response to on-going long-term stress situations which do not require a fight or flight response (for example, stressful work environment or stress due to marital problems).

In response to an acute stress, the body releases certain hormones and neurotransmitters. Basically, the response to any stress involves the hypothalamic-pituitary-adrenal axis (HPA axis).



A little briefing on what the above three mentioned are:

~ Hypothalamus - is a region in the brain which helps regulate body functions, providing a link between the nervous system and the endocrine system. It secretes releasing hormones (RH) in response to stimuli, which control the release of hormones by the pituitary gland.
~ Pituitary gland - a gland located at the base of the brain which releases hormones (that regualte a wide variety of body functions) in response to RH from hypothalamus.
~ Adrenal gland - gland situated above the kidney, and regulates stress by synthesis and release of catecholamines and corticosteroids.

So basically what happens is, when you are under stress your hypothalamus gets stimulated to secrete Corticotropin-Releasing Factor (CRF). The CRF acts on the pituitary gland and hence Adrenocorticotropic Hormone (ACTH) is realeased. The ACTH stimulates the adrenal glands to release Catecholamines and Corticosteroids (glucocorticoids - cortisol).

All the changes that occur in the body during stress are primarily due to release of catecholamines and cortisol. The major catecholamines are epinephrine, norepinephrine and dopamine. The catecholamine which plays the key role in stress related changes is epinephrine, also known as adrenaline (the stress hormone).

One of the effects of these hormones is on the amygdala - a region of the brain which manages emotions. In this case, it would cause fear. The hormones also signal the hippocampus (the region of the brain which is responsible for long-term memory), to store this experience for further reference. It helps to identify the same experience as one of fear/terror when you come across it again in the future. Also, the frontal brain (the front portion of the brain responsible for short-term memory, concentration, inhibition and rational thinking) is inhibited during a stress response. Hence, it can hinder the ability of a person to make rational/complex decisions and to concentrate (especially during exam stress).

Chronic stress on the other hand has very devastating and harmful effects on the brain and the rest of the body. During chronic stress, the body detects small levels of stress and keeps the nervous system slightly elevated causing release of stress hormones in extra amounts over a prolonged period of time. Studies have shown that chronic stress results in a shrinkage of the hippocampus with reduced blood supply, and hence causes a reduced acticity. Also, it is found that the amygdala increases in size and remains hyperactive, regardless of the stimuli.

The result of a shrunken hippocampus and an enlarged amygdala is not good. The huge amygdala causes anxiety and fear to even very small stimuli. The shrunken and inactive hippocampus makes it diffcult for you to process and recall the intial or the specific stimuli that caused your stress. Hence, the body will remain confused as to the specific cause of stress/fear/anxiety. The result will be that your body will stimulate the amygdala to cause generalized anxiety and fear.

In the next post, I will discuss specific changes in the body in response to stress.