Overview

Essential tremor is a nervous system condition, also known as a neurological condition. It causes rhythmic shaking that you can't control. Essential tremor can affect almost any part of the body, but the trembling happens most often in the hands. The trembling occurs especially when doing simple tasks, such as drinking from a glass or tying shoelaces.

Essential tremor usually is not a dangerous condition. However, it typically worsens over time and can be severe for some people. Other conditions don't cause essential tremor, but essential tremor sometimes is confused with Parkinson's disease.

Essential tremor can happen at any age but is most common in people age 40 and older.

Symptoms

Essential tremor symptoms:

  • Begin gradually. They usually are more noticeable on one side of the body.
  • Worsen with movement.
  • Usually happen in the hands first, affecting one hand or both hands.
  • Can include a "yes-yes" or "no-no" double nodding or shaking motion of the head.
  • May worsen with emotional stress, fatigue, caffeine or extreme temperatures.

Essential tremor vs. Parkinson's disease

Many people link tremors with Parkinson's disease. But the two conditions differ in important ways, including:

  • Timing of tremors. Essential tremor of the hands usually happens when using the hands. Tremors from Parkinson's disease are most noticeable when the hands are resting at the sides of the body or in the lap.
  • Related conditions. Essential tremor doesn't cause other health problems. However, people with essential tremor sometimes develop other neurological symptoms, such as an unsteady walk. Parkinson's disease is linked to stooped posture, slow movement and dragging the feet when walking.
  • Parts of the body affected. Essential tremor mainly involves the hands, head and voice. Parkinson's disease tremors usually start in the hands and can affect the legs, chin and other parts of the body.

Causes

About half the people with essential tremor appear to have an altered gene. This form of the condition is referred to as familial tremor. It isn't clear what causes essential tremor in people who don't have familial tremor.

Risk factors

Known risk factors for essential tremor include:

  • Altered gene. The inherited variety of essential tremor, known as familial tremor, is an autosomal dominant disorder. That means an altered gene from just one parent is needed to pass on the condition.

    Anyone who has a parent with an altered gene for essential tremor has a 50% chance of developing the condition.

  • Age. Essential tremor is more common in people age 40 and older.

Complications

Essential tremor isn't life-threatening, but symptoms often worsen over time. If the tremors become severe, it might be difficult to:

  • Hold a cup or glass without spilling.
  • Eat without shaking.
  • Put on makeup or shave.
  • Talk, if the voice box or tongue is affected.
  • Write legibly.

Prevention

There is no known way to prevent essential tremor.

By Mayo Clinic Staff