Hi, Over The Years I Have Experienced A Sort Of

Hi, over the years i have experienced a sort of severe chest pain. It comes in waves, meaning it happens very fast and all at once but happens about once or twice a month. It's a sharp pain that starts in the muscle area right over the front side of my rib cage than sometimes migrates all over the front of my lungs. It doesn't hurt the inside of my lung, just the muscle that covers it. As i said before it's sharp and makes it extremely difficult to breathe due to the fact that as i expand my lungs while breathing in the rib cage brushes against the muscle and that pressure hurts. The only way i can make it go away is to lie down on my back so all the pressure is taken off the front side of my rib cage. I have seen specialists and doctors but they have no idea what's wrong. I was wronging if you had any ideas as to what this could possibly be.