Essential tremor (ET) is a nervous system (neurological) disorder that causes involuntary and rhythmic shaking, often in the hands and arms. Although the condition is not life-threatening, there are severe cases that involve disability.

Parkinson's disease is a neurological disorder that happens when nerve cells in the brain don't produce enough dopamine. This condition deteriorates over time, leading to greater disability.

Essential tremor and. Parkinson's disease differs in key ways:
  • Timing of tremors – Essential tremor of the hands usually occurs during hand movements. Tremors from Parkinson's disease are most prominent when hands are in resting positions.
  • Associated conditions – Essential tremor does not lead to other health problems, whereas Parkinson's disease is associated with stooped posture, slow movement, and shuffling gait. However, people with essential tremors may develop other neurological signs and symptoms, such as an unsteady gait (ataxia).
  • Parts of body affected – Essential tremor mainly involves your hands, head, and voice. Parkinson's disease tremors usually start in your hands and can affect your legs, chin, and other parts of your body.