hi im 24 years old i have another post on here about my heart it will race to 100 once and ahwile my bp is normal,and my rib cage seems tender and achy alot i dunno..anyway i went back to the dr he listened to heart,looked at ekg result,and said he thinks im fine im 24 etc..said run full blood work up,but how do i know for sure i m so scared any ideas...