Essential Tremor usually affects the hands or arms, but it may also affect the head and neck (causing shaking), face, jaw, tongue, voice (causing a shaking or quivering sound), the trunk and, rarely, the legs and feet.
The tremor may be a rhythmic "back-and-forth" or "to-and-fro" movement produced by involuntary (unintentional) contractions of the muscle. Severity of the tremors can vary greatly from hour to hour and day to day.
