Mary
I was diagnosed with Tietze's/costocondritis a year ago, although I've had it for 8 years. There isn't much I've found to relieve it. It is best to just avoid things that trigger a flare up. For me, avoiding caffeine, not lifting, or holding, heavy objects, on the affected side, and avoiding sleeping or laying on that side helps prevent it from getting worse. Also, trying to relax helps. Tension only makes it worse. I know first hand that flare ups are frightening, but try to remember that you at least aren't going to die from one. (Even though that's what it feels like)