Insight meditation generates both mental and physical healing power, and while this sounds somewhat mysterious, the explanation is simple. A person who can control his mind, through refining the practice of sila (morality) and sati (mindfulness), will not be as stressed in performing his daily tasks, and, so, will be more positively balanced, and, therefore, more effective in his efforts, on both mental and practical levels.
On this point, Luang Por Viriyang has said (in his Instructions for Meditation Teachers, Book I), that the meditative mind is an effective rest which promotes positive thinking and management capability.”
Conversely, he also says, “the movement which is the vibration of the brain can become severe on some occasions,” ─ and such severe moments can create severe impacts and result in severe effects.
We all know from experience how such severe mental movements can cause problems in life.