In the last month I've experienced odd chest pains accompanied by panic attacks, rapid heartbeat, right arm numbness, stiff neck, nausea and extreme fatigue. The symptoms feel as if I'm having a heart attack and lasts. The emergency room doctor and my doctor have ran blood test, done an ekg ect. They prescribed me antacids that make it worse. The blood test came back absolutely normal accept elevated carbon dioxide in my blood and my ekg was also normal. I don't drink or do drugs but I do smoke about 7 cigarettes a day. I eat rather healthy no carbonated sodas, no caffeine, no fast food. What could be causing the elevations? And should I be concerned?