Can gas build up cause pain in your left arm? i don't have any chest pain, dizziness, shortness of breath. just gas, belching and mild left arm pain.

Seek medical consult: What you describe may (or may not) be serious. You should seek medical consultation right away, so that a doctor can get more information, & advise you appropriately. HealthTap consultations are available; just start over & click on Talk-to-Dr. You can choose video or text, & you can upload pictures, or documents such as test results. Or, call your doctor's office. I hope you feel better soon!