I have this stabbing pain at the top of my left chest were my muscules r the pain has been coming and going for the last few hours . Sometimes it moves from one side to the other and it comes and goes . I don't think it's a heart attack am 20 and have had many ecg to check my heart in the past . It's just really terrifying AV had similar pain to it before . It seems to relief when I take deep breaths . I guess j just want some reassuring from anyone who has had this that its just anxitey causing the pain or the muscules to tighten . Really freaked out can't stop crying please help