Essential tremor (previously also called benign essential tremor or familial tremor) is the most common tremor disorder. It usually involves shaking of hands and is more pronounced when the limb is in use or action. The exact cause for essential tremor is unknown. Essential tremor is one of the most common of neurological movement disorders affecting about 5% of the population over age 40. Though more common in the elderly this can occur at any age and involve other body parts such as legs, head, trunk and vocal cords. At times, this is seen in association with other neurological conditions. Though it does not influence the life expectancy of an individual, it can interfere significantly with simple daily tasks. Patients may experience trouble with writing, using utensils to eat and drink, taking care of personal hygiene including shaving.
Other types of tremor are physiologic tremor, dystonic tremor, cerebellar tremor, Parkinson tremor, orthostatic tremor and psychogenic tremor.