The only thing I know for sure is that the more you test yourself, the worse you feel with increase in anxiety...then your mind starts making things up. Don't test yourself....easer said than done as we all do it. I think we all feel things in our body that are normal but with our higher state on self concern, we take those symtoms and run. Most "normal" people would blow it off and keep going and the symtoms go away. I want to be one of those "normal" people.