Tremor is the shaky movements of your hands, limbs, head or voice that you can't control. Sometimes tremor is a normal reaction to a situation such as fear, fatigue or anger. It also can be a side effect of too much caffeine, a medication, or withdrawal from a drug or medicine. When tremor occurs during activities and there is no emotional or chemical cause, it can be a sign of a neurological disease called essential tremor.
Essential tremor is different than Parkinson's disease, another neurological illness. Essential tremor is most noticeable when your body is in action, such as when you are writing, typing or pouring a beverage. In contrast, the tremors of Parkinson's are more noticeable at rest.
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