Essential tremor is uncontrollable shaking or trembling of part of the body that lasts for at least a few seconds. It is a common movement disorder that usually affects the arms and hands, but can affect the head, jaw, face, feet and tongue. Sometimes the voice can sound shaky.
'Normal' tremor
Everyone has a very minor tremor when carrying out daily activities. For example, your hands will shake slightly when you hold them out in front of you. This is physiological tremor and is normal.
From time to time, this everyday level of tremor can become more noticeable, especially in older people. Noticeable tremor is also normal and often caused by a raised level of adrenaline in the body, which can happen when you are stressed, anxious or angry. It can also occur when you are on some medications, such as inhalers for asthma.
When does it become a disorder?
Essential tremor occurs frequently. It gradually becomes more noticeable over the years and is unrelated to the causes of normal tremor. The tremor may eventually become so severe that it is difficult for you to do normal activities.
Essential tremor is made worse by the same factors that exaggerate normal tremor, such as stress, anxiety, anger, strenuous activity, caffeine and some prescribed medicines.
It will get worse when you try to do simple tasks such as drinking a glass of water, tying shoelaces or writing. It is not usually present when you are resting.
How common is essential tremor?
Essential tremor affects men and women equally and can affect people of any age, although you are more likely to develop it as you get older. Nearly 5% of elderly people have it.
Essential tremor can run in the family.
Outlook
Essential tremor doesn't affect life expectancy. For most people it's a minor nuisance, but gets slowly worse over time. At worst, it is disabling and makes daily activities very difficult.