Hey
okay, so i am 15 years old male (turning 16 next month). My heart rate used to feel normal (no hard pounding or fast pounding for no reason). Then One month ago there was this time where, out of nowhere my heart started beating really, really fast, and i couldn't breathe properly and so my parents took me to the hospital. Once i reached there, they checked my heart rate, and it was about 108 beats per minute, then eventually returned to normal. They did ecg's, x-rays, checked my blood pressure, and did all the tests. Then they told me everything was fine, and maybe it was a lack of water (dehydration), and to not worry about it. For the past month (after i went to the hospital about the fast heart rate), i have been having this breathing problem, where it goes on and off, sometimes i can breathe just fine, and sometimes i have trouble breathing. Now, since yesterday, it feels like my heart beat is pounding hard (not fast but hard), I am checking my heart rate at the time where it ranges from 84 to 90 beats per minute. Why does my heart feel like its pounding harder now? Is this a problem? Should i get it checked? And also i can see my heart pounding a little through my chest when i take my shirt off now. (is this a problem, i think i couldn't see it before, but maybe i didn't pay that much attention before?)
Only serious answers please! No jokes please, im only 15!
Additional Details
by the way, I am 5'11 or 5'12 and weigh about 130-140 pounds
Also, my heart is beating a little faster than it use to (i think)
~~It never happened before, so.. i didn't used to pay attention to it i guess.. now all i do is keep thinking about it and consistently and checking my pulse.... (also sometimes, for a little while i cant breathe properly, not all the time though)
Thanks to all those who took their time to give me an answer.