I have some pain on the left side of my chest.im 37 had a run on sunday and pushed myself to hard i guess.my left arm a bit num as well.

E.R. can evaluate: A person with pains in the chest and left arm can seen by an ER doctor to be evaluated. Pains can come from a heart problem (serious), neck and shoulder muscles, the ribs and their joints, the lungs inside the chest, etc... If one feels his pain is coming from the heart, has a chest tightness, some difficulty breathing, or has past heart disease, he can go to the ER by ambulance if that's fastest.