Diseases

A rhythmic, involuntary muscular contraction characterized by oscillations (to-and-fro movements).

Persons most commonly affected: All age groups and both sexes.
Organ or part of body involved: Neurological System
Symptoms and indications: The symptoms of essential tremor include: Voluntary muscles are affected. The hands, head and voice are most commonly affected. Head nodding, if the head is affected. Shaky, quivering voice - if the voice box (larynx) is affected. The tremor is usually mild, rhythmic and fast. The tremor is exacerbated by activity or movement. The tremor eases when the body part is at rest. The tremor stops when the person is asleep. The condition worsens with age. Other body parts that may become affected, in time, include the arms and eyelids. The legs are rarely involved.
Causes and risk factors: Essential tremor is the most common type of tremor, and affects more people than Parkinson\'s disease. Some estimates suggest that around one in five people over the age of 65 years are affected. There is no known cause, but a genetic link is strongly suspected. Each child of a person with essential tremor has a 50 per cent chance of inheriting the disorder themselves. If a person with essential tremor has other affected family members, then the disorder is called \'familial tremor\'.
Prevention: Certain factors are known to worsen the condition, including: Emotional stress, caffeinated drinks, alcohol and insufficient sleep.