Bad chest pain radiating to back and down left arm. went to er & normal troponin, normal ekg, normal chest x-ray & normal d-dimer. what could it be?

GI? Muscle?: Probably the most common non-cardiac pain in a young man is caused by esophageal spasm, reflux or gastritis. Muscle strain/cramp can also cause this. The chest x-ray should have excluded something serious like aorta problems. I see you do have anxiety...anxiety can also be at the root of chest pain like this. Practice your relaxation techniques, use meds as directed, see your therapist/counselor.

See below: Chest pain can result from organs in the chest: heart, lungs, pleura and from the chest wall: costochondritis. Heart conditions range from coronary artery blockage(less likely at 19 years old) to mitral valve prolapse and hypertrophic cardiomyopathy. Insufficient information to give specific advice. For patient info see: http://bit.ly/1KCXC9E and http://bit.ly/1ElGjHc Consult your physician