Hand Tremor

I’m 42.

I’ve had a twitching finger of my left hand for 3 or more years. Rigidity in my left forearm muscles off and on. I can put my left hand in my pocket and my hand will try to twitch or tremor and my forearm muscles go stiff.

Over the past 6 months my whole left had shakes increasing while I walk or am at rest. At rest... let’s say letting my arm just hang down while sitting, it will tremble and my hand will open and close quickly, non-stop unless I focus on it. I tend to walk pinching my fingers or making a fist most of the time now, so that others don’t see my hand trembling.

Typing with my left hand is tougher some days. I find my fingers in my left don't work as well. Also some loss of coordination. Like if I try to slap my hands as though playing the bongos, my left hand doesn't do it well and gets out of synch.

My left elbow nerve does feel a little more 'on fire' now and then.

My left shoulder aches a little now and then.

I do have a little bit of a stiff neck. If I bend my neck pushing head towards my left shoulder, it is stiffer than bending the other way. This has been for 3 years also. A little longer than my finger.

I've thought Parkinson's, Carpal tunnel, pinched nerve, and other things. Which all lead me to no conclusion. But the hand tremble is increasing and I try hard to hide it from others when I walk or while Ilet my hand hang down. I tend to hold my left hand in my right while talking to others.

Any suggestions as to the cause?