I have a lot of left arm pain (along with pain in so many other places!) Lately, I've been wondering about
my bra straps (if you're female). I have big indentations in my shoulders where my straps are. I just ordered some strap cushions. We'll see if that helps. Also, do you tend to sleep on that side? Are you right-handed? Do you hold a large iPhone with your left hand? Sometimes the opposite arm actually does more work than your "main" hand. There are lots of non-cardiac possibilities...
But I think it would really calm you if you saw a cardiologist and maybe had a stress echo. I'm in the same position..........I'm worried about
my various chest/arm pain issues, but I put off seeing a cardiologist......mostly because the pains aren't connected with shortness of breath, working hard, etc. But sometimes, even when we really don't think it's something, we feel so much better if we rule out certain problems by going to the doctor. Now.......if I could just practice what I preach!