Tremors are involuntary, rhythmic movements of one or more body parts. Essential tremor is the most common type, and it usually occurs in healthy people. In fact, tremors themselves are not life-threatening. However, some tremors are symptoms of other diseases or conditions that can be serious.
In most cases, tremors are caused by problems in brain areas that control muscles or muscle groups. They can also come from certain drugs, from thyroid or liver problems, from muscle fatigue or other causes.
Physiologic tremor. Everyone has a small tremor – to test this, hold a sheet of paper out at arm’s length. The paper will tremble, if only just a little. This physiologic tremor is usually not noticeable, but it can become exaggerated in some circumstances. For example, stimulants such as caffeine and nicotine can cause tremor. Tired muscles can become shaky, and extreme emotion such as fear and anxiety can cause tremors. People with an overactive thyroid may also have tremor. These tremors usually go away when the underlying cause is resolved – for example, treating a thyroid problem or avoiding stimulants.
Drug-induced tremor. Taking medications such as steroids, some drugs for asthma and others for neurologic or psychiatric disorders can cause tremor. The specific type of tremor – whether it occurs at rest or during action, the degree of movement and other characteristics – depend on the drug. Switching to another medication or lowering the dose often relieves the tremor.
Essential tremor. This is also called familial tremor, since it often runs in families. Up to 5 percent of people have this condition, which usually starts later in life but can occur at any age. It’s not connected to another health problem, but it can get more severe over time. Besides shaky hands, people with this condition may have tremor in their head that results in a “yes-yes” or “no-no” movement. The voice can also sound shaky. Mild essential tremor may not need treatment. For more severe symptoms, doctors may prescribe medications called beta blockers, or anti-seizure or anti-anxiety drugs. Some people with severe essential tremor that doesn’t respond to medication have a treatment called deep brain stimulation, which involves a surgically implanted device.
Parkinsonian tremor. Unlike essential tremor, which occurs when you move deliberately, Parkinsonian tremor usually happens when your muscles are relaxed. This tremor is named for Parkinson disease, and it is often the first symptom of that condition. But the movement of Parkinsonian tremor, which include a “pill-rolling” movement of the hands, can also occur from certain medications, vascular problems or other diseases of the nervous system. Medications can often relieve tremor from Parkinson disease, and deep brain stimulation may help people who don’t respond to drug therapy. Parkinsonian tremor from another condition may resolve when the underlying condition is treated.
Cerebellar tremor. This tremor occurs with deliberate movement, not rest. It is caused by damage to the brain from stroke, trauma, multiple sclerosis or other problems. People with cerebellar tremor may also have balance problems, uncoordinated movements and slow, slurred speech.
There are also a number of unusual or rare tremor disorders, including primary writing tremor, which occurs only while handwriting. Orthostatic tremor happens when the person stands up but disappears partially or completely with walking or sitting. And a condition called Wilson’s disease causes a “wing-beating” motion when the arms are extended.
Ken Field treats his essential tremor by avoiding caffeine and trying to minimize stress – another tremor trigger with this condition. He also takes a beta blocker. Field continues to play guitar and other instruments despite the challenges.
If you have a tremor, it’s a good idea to check with your doctor. He or she may be able to recommend something to relieve your tremor or treat the condition that is causing it. Find out more about tremors by visiting the National Institute of Neurological Disorder.