Essential tremor (ET) is the most common pathologic tremor in humans. The traditional view of ET, as a monosymptomatic condition, is being replaced by an appreciation of the spectrum of clinical features, with both motor and nonmotor elements. These features are not distributed homogeneously across patients. In addition, postmortem studies are now demonstrating distinct structural changes in ET. There is growing evidence that ET may be a family of diseases rather than a single entity. Furthermore, this aging-associated, progressive disorder is associated with neuronal loss and postmortem changes that occur in traditional neurodegenerative disorders.