I Am Having Pain And Tingling From My Shoulder To

I am having pain and tingling from my shoulder to my fingers in my left arm. i have not had any recent injury to the arm, I was having chest pains so went in to my doctor last month and did a stress and rest test and everything came out fine. What could be the cause of the pain and tingling? It is like my arm went to sleep and is waking up, but has been getting worse over the past few hours. This has been going on now for 5 hours.