Physical Impact of Stress on the body – Part 1 12 Feb 2020
Stress is a natural human response that enables the body to cope during certain situations.
There are three phases to our stress response:
Phase 1 - The Alarm Phase
Phase 2 - The Resistance Phase
Phase 3 - Exhaustion
Phase 1 - The Alarm Phase
This phase is short lived and initiated by the hormones released by the adrenal medulla. It is triggered by excitement, exercise, emergency and embarrassment - what are commonly called the "E" situations.
During this phase the sympathetic nervous system will dominate and favour body functions that support vigorous physical activity. Once the situation is resolved the body either the parasympathetic nervous system will dominate allowing the body to relax and digestion food or the sympathetic nervous system will continue to dominate and the body will move into phase 2.
Phase 2 - The Resistance Reaction
This is a long term stress reaction or chronic stress and it initiated by the hypothalamic releasing hormones:
During phase 1 stress response the heart rate is increased to increase the rate of blood flow as blood is directed away from the digestive system and digestive organs towards the skeletal muscles of the body. Drawing blood away from the blood away from the stomach for too long can lead to indigestion or IBS. In addition, corticotropin is the body's hormone alarm bell telling it to release steroids and adrenaline, increased exposure can lead to IBS, stomach aches, nausea, diarrhea and heartburn.
All the body functions are impacted as the body's pH is increased. The body's sodium levels are increased increasing water retention by the kidneys and maintaining the increase in blood pressure during the alarm phase. This increase in blood pressure and blood flow helps the body cope with the demands placed upon it but in the long term can lead to hypertension.
The stress hormones cause the blood to become thicker and stickier increasing its ability to clot to help the body cope with injury. Chronic stress where there is thicker blood and no injury can lead to blood clots and therefore affect the blood flow causing damage to the heart. The increase in the heart rate and force of the contractions of the heart in chronic stress can lead to an abnormal heart rhythm causing heart muscle damage.
Adrenaline and cortisol trigger the release of fatty acids into the blood stream for the body to use as energy. Prolonged release by cortisol can potentially increase cholesterol levels leading to a thickening of the lumen and hence a narrowing of the arteries. Continued exposure to cortisol can increase abdominal fat, therefore increasing the risk of heart disease.