Have you ever felt like your heart was racing during normal activity?

Is your heart actually beating fast, or is it just beating hard, like you have the sensation of a pounding heart without the fast beats? If its the latter, that's called palpitation and it's basically being aware of one's heartbeat. I experience it alot and for a while it really freaked me out. I went to see my doctor a few times when I first experienced it and they ran me through an EKG or two and found no abnormalities other than a little bit of high BP. I am 26 years old, 5'-11, 155 lbs but I have a strong family history of high BP. I'd suggest seeing your doctor without getting too stressed out about it! For me, its more about getting worked up over the sensation than anything else!

It's not actually beating faster, it just feels like it's beater harder/faster. I went for an EKG and they said it was normal, they're going to have me wear some type of monitor for a few days (I don't think I can run or workout in it), but the doctor didn't seem to think anything was abnormal.

Get your thyroid checked out.