question: Hey there, I'm a 17 year old male and my left arm's feeling a bit funny, it's a little numb and now's  a wee bit weaker than my right arm. The left part of my chest also feels a little funny, not sure how to describe it, but it does not feel as usuall. I am getting a little worried cus' I can't really tell if this "whatever I feel" is on the inside or the outside of my chest. It's been like this since yesterday night. Now I suspect that this might have something to do with me swimming three days ago, might have streached a muscle or something but it's really hard to tell. Could it be that it has something to do with my heart? ( Yes that's what I'm worried about ) I mean, I don't smoke, don't drink. I walk atleast 40 minutes per day, usually more and I also attend to Athletic class in school. I'm not overweight, I'm actually rather skinny, but I have been eating more fat products these latest weeks ( Crisps etc ) But only once a week, so yeah, could this be serious or is it just me acting silly? Thanks.