To clarify, the pain has not been persistent for a year and a half. It comes and goes, with no predictability. It does seem like it occcurs more frequently; in fact, this weekend is the first time it did not subside after a day or two.
Also, it occurs just to the right of my breastbone, beneath my front collarbone. It is not painful or sensitve to touch or manipulation, though tilting my head back seems to increase the pain level, which can be a dull pain or, as it has been since Saturday, a frighteningly sharp pain. It feels like if I took a real full breath, something would pop, or rupture.
The first time this happened, I went to the ER, with no relief or answers. Followed that up with an appointment with a Dr. at an internal medicine group here in town. Did a pulminary function test-- I performed well.
As I told you, I also did a stress test (on the treadmill that tilts) and did well. What is a nuclear stress test?
Finally, after reading your initial response, and thinking out what's been going on, I do feel fairly confident that this is not cardiac in nature.
Any response?