A sudden chest, back and left shoulder and arm pain for about 30minutes. What is it? And should I see a doctor?

Must call the doctor. Any person with chest, left shoulder, and left arm pain symptoms has to go to his doctor or the E.R. to be checked right away for a heart attack. That means not waiting at home to see if it becomes a bad heart attack. It could turn out to be a lung problem, a bone or muscle problem, or an acid reflux problem, but the heart attack kills people. As the saying goes, "better safe than sorry".