Essential tremor is a movement disorder characterized by shaking that you can't control. Such a tremor is involuntary, small repetitive, rhythmic shaking or twitching. The condition is sometimes called benign essential tremor.
Essential tremor may start in the hand or fingers. The shaking may increase or spread to other parts of the body over time, such as the head, feet or torso. Essential tremor doesn't cause other health problems, but it can make completing everyday activities more difficult. For instance, your hand or fingers may shake when you lift a cup or point at something. Or your voice may shake when you speak.