It is the most common form of tremor . If an essential tremor occurs in more than one member within a family group it is termed a familial tremor .
Tremors occur at any age but are most common in older people.
It involves a rhythmic, moderately rapid tremor of voluntary muscles. Purposeful movements may make the tremors worse. Emotional stress may also increase the tremors. An essential tremor rarely involves the legs or feet. The cause is unknown.