Every once in a while when I am holding something in my left hand, I can see that my hand is really shaky. It's almost as if I have Parkinson's or something. But, its only my left hand, my right hand is completely steady. The intensity of the shake also varies from time to time. I really noticed it tonight when I was trying to hold a piece of paper to read something and it was shaking so bad I had to switch it to my right hand. nothing else on my body shakes, only my left hand from time to time. It might be shaking a lot tonight because I strained my left forearm lifting weights, but even on other days, it'll still shake, but not as bad. Is it possible to have something like parkinson's only effect one arm? I am 24 years old, and I shouldn't have a problem steadying my hand. Is this normal?