Definition of Tremor:

Tremors are a type of involuntary shaking movement. Involuntary means you shake without trying to do so.

See also:

• Drug-induced tremor
• Essential tremor
• Familial tremor
• Hand tremor

Causes, incidence, and risk factors:

Tremors are caused by problems with the nerves supplying certain muscles. They may affect the whole body or just certain areas, as with hand tremor.

Types of tremors include:

• Drug-induced tremor (tremors caused by certain drugs)
• Essential tremor (no known cause)
• Familial tremor (runs in families)

Other causes of tremors may include:

• Alcohol withdrawal
• Cigarette smoking
• Hyperthyroidism
• Parkinson's disease
• Pheochromocytoma
• Too much caffeine
• Use of certain medications
• Wilson's disease

All people have some tremor when they move their hands. Stress, fatigue, anger, fear, caffeine, and cigarettes may temporarily worsen this type of tremor.