[L. tremor, a shaking]
1. A quivering, esp. a continuous quivering of a convulsive nature.
2. An involuntary movement of a part or parts of the body resulting from alternate contractions of opposing muscles.
Tremors may be classified as involuntary, static, dynamic, kinetic, or hereditary. Pathological tremors are independent of the will. The trembling may be fine or coarse, rapid or slow, and may appear on movement (intention tremor) or improve when the part is voluntarily exercised. Tremor is often caused by organic disease; it may also express an emotion (such as fear). All abnormal tremors except palatal and ocular myoclonus disappear during sleep.
Conditions or diseases that aggravate tremor include alcohol withdrawal, amphetamines and other stimulants, anxiety, beta agonists, caffeine, fever, and sleep deprivation.
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