The body responds to a stressful situation with either anger or grief. In either case, the body tries to prepare for a fight or flight, against an actual or imaginary enemy or situation. This preparedness of the body requires certain physiological changes, that are mediated with the help of hormones like adrenaline, growth hormone, dopamine, etc.
Adrenaline has the following actions, that prepares us for a fighting situation:
- raised hair (in animals, makes them look bigger and more menacing)
- eyes opened wider (to see better) and focused for distance vision (to locate the enemy from far)
- moist perspiring skin (so that the enemy cannot get a firm grip on the body)
- breathing more in rate and depth (to draw in more oxygen)
- heart rate faster with higher blood pressure (to deliver more blood faster to the muscles). Persistent raised rate can damage the heart.
- lower blood flow to abdomen (to divert more blood to muscles and brain)
- higher blood sugar and lipids (cholesterol and triglycerides) to provide more fuel to muscles for energy release. If the lipids are not used up, they may clog arteries to raise blood pressure permanently and cause heart attack or stroke.
- increased clotting tendency of blood, to reduce bleeding risk from trauma during a fight. In the long run, this may aggravate risk of blood clots leading to a heart attack or stroke.
- increased tension in muscles, since muscles under a slight tension can contract more powerfully. In the long run, constant muscle tension causes fatigue, weakness and muscle pain.
Each of the changes are very useful when fighting. However, when the stress does not end in a physical fight, and is long drawn or constant, then these same changes backfire to cause lasting damage as mentioned.