
The external and the internal forces are two opposite features and related to each other. One is to attract and the other one to react and act. However, when internal force becomes weaker to external force, the inability that we face creates the stress due to strain resulted by helplessness. The external force is also a creation by us to live with it through our ambitions, desires, and the activities etc. The external force is the environment or what we call is the situation that attracts us to react. The reaction when fails to match despite the efforts and deep involvement makes us desperate and we fail to go with it. Internal force is our own self, the personality.
Our personality is always ahead of us that influence us to act according to its requirements and desires. Our brain and body as tool act to fulfill the directions. The process of direction and action is through the chemical reactions in the body. Success and failure are the reaction of chemical substance that cheers us up during success and sadden when fail. Our brain cells too get confused during the act, due to extreme involvement towards the goal whether for happiness or sadness. The brain fails to act in its extreme functioning as the machinery in its extreme overheats and collapses. We can sense this situation when we find ourselves in vacuum and nothingness. Is a confused position or stressed and to overcome the situation we have to forget what we intended in our mind and relax until cools down.
http://www.sadashivan.com/thequotstressquot/index.html