Relaxation is a learned behavioral response that in many ways is the opposite of the stress or anxiety response.
Unfortunately, throughout our lives we are continually being stimulated to produce the stress and/or anxiety response, but we have few stimuli prompting us to relax. This causes a gradual increase in our ability to react with stress and anxiety responses and a gradual diminishment of our ability to relax. I see this every day in medical practice where people who are stressed and anxious simply have forgotten how to relax properly. In terms of improving one's quality of life and reducing the effects of stress and anxiety, relaxation is simply the best and most effective behavioral response.
The good news is that relaxation can be relearned and if practiced enough, can be used to overcome the learned and often practiced stress and anxiety response.
In my own life, I often practice a simple relaxation technique. When I am feeling stressed or experience that "butterflies in my stomach" feeling, I do a simple routine of slow deep breathing while concentrating on my breathing. It is important that this be done slowly since hyperventilation, that is, rapid shallow breathing, will facilitate and exacerbate the stress and anxiety response. I focus on slowly and deeply breathing in and then I really don't have to focus on breathing out, my body will do that automatically. It amazes me sometimes how well this works and you can make this work for you too, but it will take practice. Remember, the stress response occurs frequently throughout our days and we become very well practiced at it. We become good at what we practice. Another way of saying that is; what we feed grows and what we starve withers. The more one practices relaxation and the more one can use this response to counteract every day stress and anxiety, the better one gets at relaxation.
There are many other techniques to help one develop a strong relaxation response. This is an important aspect of everyone's life and particularly when one is dealing with chronic pain and associated problems. There are many books available that one can utilize to learn relaxation techniques, but there is no substitute for practice and lots of it. When one becomes good at relaxation, many other problems can begin to dissipate.
You, the individual, are responsible for your level of stress response and for your ability to counteract this with a strong relaxation response.
There are significant spiritual aspects of this concept that I will discuss under the title of "Spirituality." Learn and practice. Relaxation can change your life and improve your health.