How often does this happen? It sounds like it could be pretty urgent

I have gad a lot of muscles misbehave. So much that one day, i have similarity to frozen sholder on one side and the next day itcwill be the other side. Same for any place the muscles can get 'knotted up' (my term). And chest a few times and a few of thise times are like the muscles get stuck to or pinched inside the rib cage (very sharp tgat breathing is hard, talking or moving impossible).

I do since i was 12 (im 19 now) it can be inflammation in your ribs/cartilage, best way to get rid of them is to lay down. Do talk to a doctor just to be sure it isnt anything wrong with your heart but if they find nothing, its most likely inflammation. And i have hEDS so ive felt the arm pain before with and without chest pain

Yes I do. I brought it up with my cardiologist last time I was there and it was noted as “chest wall pain” not really having to do with my heart. I am waitlisted for genetic testing for EDS and I think it’s likely right muscles. Heating pads helps for me. It relaxes the muscles some I think. It’s scary and it’s worse that I can’t calm myself with my normal deep breaths because it hurts 😣