Im 21 and I experience the same thing...I would get checked out just to make sure you rule out anything physical...Im guessing your fine cuz ive had to deal with the same thing...I ended up in the ER the first two times it happend thinking I was have heart problems but everything was fine...I think your a little young to be having heart problems but if they persist and get worse Id go get an evaluation by your doctor...
Sorry you have to endure this, hope things get better
Forgot to add one more thing..since you describe pain at night, I would also have to wonder if it isn't GERD which can also cause a rapid pulse and cardiac like symptoms. Try not to eat for 2 hours before going to bed, you could try taking one of the over-the-counter acid reducers, and watch the caffeine and chocolate! Like I said, I have been where you have been. Please don't call yourself a "Hypochondriac." Don't be afraid to talk about it and get the help you need. It is obviously affecting your life and no matter what it is, it is very real and very scary to you! Big hugs to you : )
Oh sweetie, I am so sorry you are having to go through this. I did too at your age. It doesn't help when you're a teenager and have all these hormones going haywire in your body! Definately anxiety can cause this and anxiety is a very real disorder and nothing to be ashamed of. I wish I could have had a way to talk about it at your age instead of feeling like a freak with a shameful secret. The pediatrition told me that they are seeing more and more anxiety in teenagers and I don't know if it's because it's easier to talk about now and there is more awareness or if kids in general are under more stress. Probably a combination of both! When you feel the palpitations, here is a good way to cardiovert yourself..Take in a deep breath and then hold it for a few seconds and actually push with it. A doc taught my sister how to do this, and I have tried it a few times. Sometimes it works, sometimes it doesn't. Please don't be ashamed to talk to your parents and your doctor about an antidepressent. At your age, it would probably only be temporary and my stave off any future increase in your anxiety.
From my experience, both of these are normal symptoms of anxiety...I get chest tightness/discomfort, intense feeling heart beats, and stomach problems...and from what I gather, most people suffering from anxiety issues have them.
Like any issue you think might be serious, you can always seek medical help, if it gets worse or if you are truly concerned. But just remember, if you think that your anxiety might be causing it, it probably is...