We all know that stress plays an important factor in the development of illnesses and can cause a variety of diseases but what do you really know what stress does to our body before an illness actually occurs? We know that when faced with stress, our body goes into overdrive and increases activity in almost every system in our body but what does it speed up?
Stress stimulates the sympathetic nervous system which speeds or increases every function of our body except our Gastro-Urinary system – that includes your stomach, intestines, urinary system, etc, in response to work overload.
Let us focus on its effect on the circulatory system - the heart and blood vessels and some diseases that would likely cause problems like high blood pressure and etc. What does stress do to our heart? Notice that when faced with danger or a major stress you can feel your heart pump harder and faster? This is the heart compensating by supplying an increased amount of oxygen and nutrients to cells which would normally be needed for other functions.
This keeps blood circulated throughout the most important and vital organs of the body, keeping us alert to the situation where it prepares our body for any imminent crisis. Along with the hearts increased rate, our arteries constrict and our airways dilate. Why is that so? Constriction of blood vessels decreases the distribution of much needed blood to our body while our airways dilate or becomes bigger in the attempt to supply more oxygen to the body. These three mechanisms help in increasing the supply of vital oxygen and nutrients to the vital organs of the body.
As blood is directed towards the vital organs of the body, some organs are excluded and less blood is supplied as it is not needed in the crisis situation such as the kidneys. How could your body think of making urine when you are facing a stressful situation?
So your kidneys are left out and because there is decreased blood flow to the kidneys, this activates the Renin-Angiotensin-Aldosterone System, which is triggered by low blood supply to the kidneys. This ultimately results in vasoconstriction, and water retention, owing to the effect of Aldosterone. These responses are made in order to increase the supply of blood to the kidneys, which were deprived.
Because of increased heart rate, vasoconstriction, and water re-absorption/retention, blood pressure increases. This does not do actual harm, however for those who have heart problems or are at risk of it, and those who suffer from other risk factors in developing illness involving the circulation like Hypertension, then it would definitely aggravate the condition. Therefore proper intervention and management is indicated in such situations.