Tremors are a type of involuntary shaking movement.

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).

Disorders with tremor as the primary symptom include:

• Familial tremor (runs in families)
• Essential tremor (no known cause)
• Drug-induced tremor (drugs known to induce tremor include valproic acid, lithium, and cyclosporine)

• Tremors
  • May be occasional (sporadic), temporary (episodic) or occurring at intervals (intermittent)
  • May affect the head, hands, arms, eyelids, or other muscles
  • May not affect both sides of the body equally
• A shaking or quivering sound to voice
• Head nodding
• Tremors that worsen with voluntary movement or emotional stress
• Tremors that disappear during sleep

Tests depend on the suspected cause of the tremor. However, a neurologic examination should be conducted in most cases.