For the last year or so, I've been experiencing random "attacks" of chest pain. It feels sort of like a cramp in my left lung and hurts very badly. It's a dull achy pain if I hold still but if I move too quickly or take a deep or sudden breath, it feels like something is ripping my chest apart. For a while it only happened every couple months but lately it's been happening more often, with a really bad "attack" and then over the next month or so some less painful ones.