I'm 25, and I've been dealing with this on-and-off pain in my left arm for about 15-20 days now. It was sharp and shooting at first, so I thought it might be gastritis, but now the pain's more dull and constant. Lately, for about a week, I've been feeling breathless sometimes, and there's some nausea too. I get tired pretty quick and now there's this annoying discomfort in my upper back. Should I be looking into any specific tests or is there something else I should be considering?

MRI of the left arm and ortho opinion is advised