As you have pointed out, this is likely to be of a psychological origin. Though getting the pain in left palm is a bit vague, it is confirmed by getting such pain again and again during a psychological upset. Also does this happen on exposure to cold as well?

It only happens as described.  I've been doing more research on this and discovered the Superficial Palmer Arterial Arch (a vein located in the hand) is primarily where the pain is.  There is also pain in what feels to be the Opponens Pollicis Muscle which is right over the Princeps Pollicis Artery.  The Princeps Pollicis Artery is connected with the Ulner Artery which is connected to the Superficial Palmer Arteial Arch.  So now I know the source of the pain... but what's causing it?  Is the vein throbbing, swelling, shrinking?  Is blood being restricted?  Would that cause pain?  I need an expert.

I have the same problem.. but i feel it in both of my palms..since i was young..and now im 18..is it dangerous?..i always feel it when im nervous, heartbroken, sad, mostly when im crying... is it abnormal?