I have been experiencing pain in the muscle going down my left arm . I did nothing to injure it directly, however during the past few days it is becoming increasingly uncomfortable and now keeping me awake. It seems to originate just below my shoulder and runs down the front of my arm, when I move or let my arm hang down it hurts even more. I have been taking anti inflammatory drugs and that alleges some but my pain is usually at an 8 or more... And seems to be getting worse