Eileen
I, too have bouts of costochondritis, albeit with much less frequency in the past 10 years. I also went the 'heart' route and wasn't diagnosed until I had suffered too many years. I only have an occasional flareup now, and since I do take Feldene for Rheumatoid Arthritis, this anti-inflammatory seems to take the edge off the pain. If you find even a posture change causes great pain, you're in the throes of a high level inflammation. I just was informed by my primary physician that this illness is viral. I was only ever told the pain came from inflammation of the cartiledge between the ribs, hence the pain when breathing. It's not contagious, but it certainly can be dibilitating. See if a different antiinflammatory might not work for you, and a pain reliever is also helpful in a flare up. I hope you get the relief you need.