Why do I have sudden fast and pounding heartbeats?

Is it normal for a slow, pounding heart?

• The slow pounding heart isn't just all. I'm nearly 16 and I'm pretty average sized, maybe smaller. I'm not really fit seeing as I do not exercise at all. I just have a really good metabolism. I've been having a random pains in my left rib under my breast, the inside of my elbow, and various other small areas such a knuckles and joints. I also get a sharp pain just below my left shoulder blade when I inhale. It was a small area of pain but it's gotten larger. This is all accompanied by a slow, but pounding heart beat and a shortness of breath after performing small and every day activities such as going up or down the stairs. Getting up to get a drink, or even eating. When I lay down at night it's pounding like I just ran a race, but the beat feels normal or even slow. Should I go to a doctor or is it just something simple like all in my head? Before it's asked, because this isn't a discussion and people tend to ask questions in their answers like I can respond, but I have recently suffered a few emotional problems. I have not suffered any physical problems or injuries other than this recently, but I do have TMJ in my jaw. Had it for over a year and a half. This all has been happening for about a month now and it's very slowly getting worse. Someone suggested fibromyalgia, but I don't ache all over. Just these certain places.

• Answer:

  you can add details to your question--look at the buttons underneath it..i doubt its fms] fms is highly overdiagnosed to begin with.. there are a LOT of things that mimic fms it could be as simple as a vitamin deficiency or dehydration look up costeocondritis gallbaldder issues will caus pain under your shoulder blades..... it could just be tension from stress