I have had major ones that have gone on for hours and that are very obviously panic attacks but it seems there also minor panic attacks that are a thing but I am not sure what counts as one. 

A couple days ago, I had to do something at work that was something I have never done before and uncertainty triggers my anxiety, what I experienced was heightened anxiety, decrease in self esteem, slightly tighter chest, slightly heavier breathing, slight headache. It didn’t really happen too long and I was fine later on, does that count as a panic attack?

I pretty regularly get a tight chest feeling with mild heavy breathing caused by anxiety, are those panic attacks?