Most of the time, when I lie flat on my back and relax, something thumps my sternum. It feels sort of like the action a sealed jar does when the seal pops up? Sometimes lying on my side helps, or twisting so my hips are flat and my torso is a bit sideways, but not always, and now it helps less and less often. The thumping has been going on for at least two years but my doctor won't even listen to my chest over it. I am 18, female.
I am posting here because it is in time with my heartbeat; it's like a sudden, hard heartbeat, although obviously it isn't in quite the right spot.
If there is a different forum I should use for better results, I'd like to know :)