Stress causes ‘Stress Response’ – it is as simple.
Stress response initiates numerous chemical, biological and hormonal changes in the body (details not important, but are well documented and available), which prepare the body for fight or flight but are generally bad for long term health.
The greater the stress, the greater the level of above changes.
If one is usually under some stress (which most of us are!), the body ‘learns’ to be in that state all the time – have you heard that some people have difficulty relaxing, even when they have no cause to stress!
Opposite of stress is being relaxed, which causes another set of chemical, biological and hormonal changes (details available but again not important), which repair and strengthen the body and result in long term health and longer life, which is a response called “Relaxation Response”.
Again deeper the level of relaxation, more are the above changes and more effective the “Relaxation Response”.
When one is mostly in this relaxed state, the body ‘learns’ this as being the default state.
In the book “Beyond the relaxation response”, Dr. Herbert Benson (cardiologist and founder of the Mind/Body Medical Institute at Massachusetts General Hospital in Boston) explains how the yogis of ancient times developed mystical powers. Using intense meditation practice they elicited extremely deep levels of ‘Relaxation Response’, which resulted in those powers.
(If you are like how I used to be, you may be inclined to gather facts to see if what I have said above is in fact true. That is a fine choice and you will find all the details. But I am sure, your time will be better spent in just practicing relaxation. Once you start seeing glimpses of the benefits I have mentioned, your need of finding evidence will go away!)