Katharine Hepburn had it. So did playwright Eugene O'Neill and Sen. Robert Byrd. Essential tremor is a condition that causes involuntary shaking.
While it usually develops in middle age, it can start much earlier. Shari Finsilver was aware of her hands shaking as a child.
"When I was about 11 years old, I noticed in art class that I was never able to draw a straight line," she says. "I really didn't know why.
