What Does Pressure In The Diaphragm Indicate?

I have been experiencing a pressure-like feeling in the area of my diaphragm. The area is not painful to the touch, it just feels like I have a pressure or a knot in that area. It does not go away if I breathe deeply or if I hold my breath. I *think* the pain began after I moved funny in a way that tends to cause painful and intense muscle spasms after a muscle in that area developed problems during a pregnancy 17 years ago. Most of the time, that area causes me no problems, but I do get those bad spasms now and then. I m thinking the spasm caused some kind of temporary trauma to a local muscle, but I want to be sure it s not something more serious. Also, if it *is* likely due to muscle trauma, I m not sure how to get it to calm down and heal up, since the area is constantly moving with my breathing. I am female. 40. family history of high cholesterol, high blood pressure, diabetes, cancer, rheumatoid arthritis.