Hi, Im 17 and for the past 58 hrs (roughly) i have been having strange tight / heavy feeling in the left side of the chest. it's on and off but mostly the feeling is there rather than not, for example i will have it for 3 - 6 hours and then it will go for a little bit before returning. It's not painful at all more so just weird and makes things hard to do physically without concern. Not sure what this is, I am told it may be anxiety. May I also add there have been no other symptoms besides this and that it appears to not improve via rest nor does it get worse through physical movement.