Essential tremor

Essential tremor, also referred to as benign tremor or familial tremor, is one of the most common movement disorders. Its cause is unknown. Essential tremor typically involves a tremor of the arms, hands or fingers but sometimes involves the head, vocal cords or other body parts during voluntary movements such as eating and writing. It is distinct from Parkinson's disease—and often misdiagnosed as such—although some individuals have both conditions. Essential tremor is commonly described as an action tremor (it intensifies when one tries to use the affected muscles) or postural tremor (present with sustained muscle tone) rather than a resting tremor, such as is seen in Parkinson’s, which is usually not included among its symptoms.