So many things can cause the problem you are having. A condition known as RSD or rather Reflex sympathetic dystrophy is a possibility. Typically this condition develops following an injury to the limb. Did you injure the area at one point? There are some cases where no precipitating event can be identified. Common symptoms are burning pain, extreme sensitivity to touch skin color changes (red or bluish) and skin temperature changes (hot or cold). Thoracic Outlet Syndrome or TOS is another possibility.
Cervical nerve root compression. Compression of the cervical nerves supplying the upper arm produces arm pain, which may worsen with movement or prolonged sitting. You may also experience muscle weakness and paresthesia (numbness and or tingling).
Heart problems can refer pain into the left arm area.
These are just some suggestions of the possible cause. Without more detail on how the symptoms developed, your medical history and examining you, it is not easy to give you the answer you want.
My advice, go see a chiropractor or you family doctor.
Posted By doc4bax on February 09, 2007 at 18:00:30:
In Reply to: Left Arm Pain That's Unexplainable
posted by Alyssa on February 09, 2007 at 14:20:25: