Most of us don't realize that we're breathing abnormally unless it's part of a panic attack. That's why you really want to keep practicing the breathing exercises when you're less anxious, so that it becomes second nature to you.
You may also want to check your posture. I had chronic back pain the entire first year that my anxiety was really bad, and it took someone else to point out that my shoulders were practically around my neck every time they saw me before I realized how much I was tensing up. At first I had to really concentrate on keeping my shoulders relaxed. Then I got into the habit of periodically scanning my body to check for tension and doing relaxation exercises if it was there. End of back pain. I've heard other people describing themselves as leaning their shoulders forward when they're anxious, which caused them pain in their chest and back muscles.
Post Edited (Little Lady) : 9/4/2012 4:44:32 AM (GMT-6)