This forum is full of stories like yours. What I always say is, anxiety is first a way of thinking and only second physiological symptoms that stem from being really nervous for long periods of time. If you're not thinking anxious thoughts or having irrational fears that are getting in your way, it's probably not anxiety. That doesn't mean there's never something not at the surface that has popped up, but you say you're feeling good otherwise. A lot of things can cause a feeling of chest tightness and palpitations -- for one thing, the chest tightness could have caused you anxiety just about that and caused you to feel your heart jump a beat, though it probably didn't actually do that -- you know, like having butterflies in the stomach before a test. That's not anxiety. That's concern about something actually happening. Nobody can tell you what caused it, probably not even a doctor at this point, but it could have been you tweaking something, something more digestive related, a muscle spasm -- all kinds of things.