Essential tremor is a nervous system disorder (neurological disorder) that causes a rhythmic shaking. Essential tremor can affect almost any part of the body but the trembling most often occurs in the hands. Essential tremor may also affect the head, voice, arms or legs.
It is usually not a dangerous condition but essential tremor worsens over time and it can become severe in some people. Essential tremor can occur at any age but it is most common in people aged 40 and older and it is not caused by other diseases.
Symptoms of essential tremor include:
- Begin gradually
- Worsen with movement
- Usually occur in the hands first (affecting one or both hands)
- May include a “yes-yes” or “no-no” motion of the head
- May be aggravated by emotional stress, fatigue, caffeine or extremes of temperature
Essential tremor vs. Parkinson’s disease
Many people associate tremors with Parkinson’s disease but the two conditions differ in several ways:
- Timing of tremors: essential tremor of the hands usually occurs with using of the hands. Tremors from Parkinson’s disease are most prominent when the hands are at the sides or resting.
- Associated conditions: essential tremor does not cause other health problems but Parkinson’s disease is associated with a stooped posture, slow movement and a shuffling gait. However, essential tremor may sometimes cause other neurological symptoms such as an unsteady gait (ataxia).
- Parts of the body affected: essential tremor mainly involves the hands, head and voice. Parkinson’s disease tremors usually start in the hands and may affect the legs and other body parts.
Approximately half of essential tremor cases result from a genetic mutation. This form is referred to as familial tremor. The cause of essential tremor in people without a genetic mutation is not known.
Risk factors for essential tremor include:
- Genetic mutation
- Age (more common in people aged 40 and older)
Essential tremor is not life threatening but the symptoms usually worsen over time. Severe tremors may cause the following complications:
- Difficulty holding a cup or glass without spilling
- Difficulty eating normally
- Difficulty shaving or putting make up
- Difficulty talking (if the voice box or tongue is affected)
- Difficulty writing legibly or in usual style