Thanks for your question. There is a small possibility that this discomfort is related to heart disease and therefore, your wife should make an appointment to see her physician for his evaluation of the problem. If her heart checks out, then most likely this is a muscular problem, shoulder strain, or arthritis of the shoulder. Problems in the neck can also cause pain in the shoulder and arm. Her doctor will be able to help her should any of these other problems be the cause of her pain.
I hope this has been helpful. Best wishes.
Martin Cane, M.D.
Hello,Did your wife possibly lift something fairly heavy lately,or reach for something and possibly lift something while streching her left arm,espically something possibly over her head?If so it is possible perhaps she might have strained her Shoulder,or a muscle in her shoulder.I would ask her if she lifted something in any of those ways,it is even possibly even at a younger age like reaching in the back of a fridge and lifting something straight up you can possibly strain your shoulder and the Muscles,If it keeps hurting i would get it checked.I know from my own experience with my neck problems,i have had times of pain down from my shoulder down into my arm,I have had bad discs in my neck and 2 neck surgeries.Jim