Pain as a Guide

It's so perfect that I wanted to blog about this topic now.  I've been up since 3am today with pain and medication issues.  My right side spinus erectus, ql muscles, and glueteus minimus muscles were in such spasm it was arching my back and abducting my right leg in rest.  So I've been up all morning with my meds, my trusty soft ball (massage), and the tv trying to get mobile again.  It's now 10 am and I may be up and moving before noon!
When you begin exercising whether you have a chronic illness or not, doctors and professionals tell you to use pain as your guide.  And...rightly so!  There is a certain amount of discomfort and minor pain inherent in exercising, but too much pain indicates you're at risk for an injury. 
BUT, HOW DO YOU USE PAIN AS A GUIDE WHEN YOU'RE IN PAIN 100% OF THE TIME? 
When it comes to the body parts that aren't involved in the chronic pain - use pain as your guide.  But, whatever body part(s) are involved in the chronic pain issue will hurt regardless or may even hurt worse during exercise.
The hardest part is to begin exercising in small, increasing segments, and listen to that pain.  Your assignment is to learn when the pain or increase in pain is simply from being up and around or moving and does it decrease to normal as soon as your done, or if you are inflaming and at risk of worsening your chronic issue.   The only way to answer this question is with gentle trial and error (ugh!).
My advise is to find a doctor who supports exercise and movement and have scans done just prior to exercise.  Begin exercising in small segments and learning about the quality of the pain you have.  Does this pain get better after a short rest after exercise or am I exacerbating my condition?  Then have regular check ups during the process and a follow up scan in 3 - 6 months to ensure that there is no worsening of the condition and you can continue to exercise.
If all is well, then just as in life, in exercise you can't let your pain stop you.  If you just lie in bed every time you have pain, you'll spend your life in bed, no Christmas, no movies, no diners out, no life.  This is the same concept with exercise you must "accept" a certain level of pain as normal and be willing to have a hightened level of pain for a short time to get the benefits of exercise.
What are the benefits of exercise?  Aside from being healthier, a healthier weight, and all the health benefits that come from that...you'll be stronger.  For many of you stronger muscles around your chronic pain sites will reduce the amount of pain you have overall and increase the number of activities and the amount of time standing up and out and about you can tolerate.  These are huge life changes for a chronic pain patient. 
So my advice is use severe pain as your guide and learn the difference between good pain and bad pain for your body.  Talk to your doctor and go make your life better.