The Online Encyclopedia and Dictionary







Tremor is the rhythmic, oscillating shaking movement of the whole body or just a certain part of it, caused by problems of the neurons responsible from muscle action.

Tremor may occur as an isolated symptom and usually of idiopathic (unknown) cause (essential tremor) or a part of the symptom constellation of another disorder (Parkinson's disease). Tremors may occur at rest (Parkinson's disease), during voluntary movements (cerebellar lesions) or during excessive activity of muscles (essential tremor, hyperthyroidism). Usually, tremors involve the hands, but they may also involve the head, face, neck, voice and legs.



There are several types of tremors. These include:

  • A rest tremor is a tremor that despite the limb being fully supported. It usually progresses at the rate of 4-7 Hz; (hertz; times per second), and is the typical Parkinsonian tremor, though it may also occur with an essential tremor.
  • A movement (action) tremor occurs when an individual tries to perform an action.
  • A postural tremor occurs when the hands are held outstretched.


Tremors may increase with anxiety and caffeine and cease during sleep. Amongst the diseases associated with tremors, essential tremor and Parkinson's disease are the best known.


Medications are used only if tremor interferes with daily life activities. Some of the drugs that can be used are clonazepam, mysoline , and propranolol.

Other tremors

Ocular tremors are eye tremors that are not problem tremors, but instead normal eye tremors believed to assist in vision. (Note: Larger eye movements called saccadic eye motion are not tremors.)

Last updated: 05-12-2005 23:54:05
Last updated: 08-30-2005 22:09:54