Do I have an underlying heart disease? 20 yr old female?

I was diagnosed with hyperthyroidism at age 18 and had a thyroidectomy (due to an enlarged gland) in Aug '04. Now I am on synthroid for the rest of my life and am living with hypothyroidism. Also, I was diagnosed with SVT (supraventricular tachycardia) in 2005 and had a cather albation in November '05. On January 31, 2007 I ended up in the ER with bad chills, a fever of 102, and unvoluntary jerking of my left arm and both feet. All of my tests came back negative and they couldn't find anything and diagnosed me with a viral syndrome. Ever since then, I've been having many more symptoms and numerous trips to the ER. I have sharp chest pain that comes and goes, upper adbominal pain, dizziness, insomina at times, fatigue, severe loss of appetite. I have lost 15 pounds in the last 12 days and I recently went to the ER a few days ago and was diagnosed with dyspnea. All my tests and chest x ray came back negative. The doctors don't know whats wrong with me! Pls help me out!

You HAVE to find an internal medicine doctor. Going to the ER over and over is not going to get you close to a diagnosis. Like the above commenter said, one doc to coordinate it all. Also, at a doctor's office, they have so many more resources to order the appropriate testing. What you're describing could be a hundred different things. It's time to find out, for certain, what it is and get the treatment you need.

I don't think someone from Y! answers can help if you've gone to the ER and they can't figure it out.

What I'd do if I were you is write down a lengthy history explaining in detail what's been going on. I would find another doctor in your area. I would let him/her know the history/consultation needs to take a while. Then read the highlights of your history when they ask you what's going on. Sometimes it helps to have everything sequentially organized and in front of you and the doctor.

I hope the best for you. 20 is too young to have these problems.
sfe
If you're only going to the ER, no one will be able to figure this out. That takes continuity of care and that means having your own family doctor and having that doctor refer you to the appropriate specialists.

Further, how is it that you honestly think someone here can diagnose you? Even if there is a doctor here, that person has not taken a personal or family history, has not examined you, has not seen the test results or read the x-rays, etc. and therefore is in no position to even attempt a diagnosis. That even if were to be both moral and legal to do so.

One doctor to coordinate all of this. One doctor, that's the key.
As per history you MIGHT had small pox infection!? The best option for you is to forget the ER, contact a cardiologist and endocrinologist and let them reach a final decision.
I am a doctor.