What is tremor? 

— Tremor is the medical term for trembling or shaking. A person with tremor has a body part that shakes, and the person cannot control the shaking. Most often this shaking affects the hands or the head, but other body parts can be affected, too. The tremor can be a problem on its own, or it can be caused by another health problem.

There are several different types of tremor. They fall into several main groups:

●Rest tremors

– Rest tremors happen while you are sitting or lying down and relaxed. People who have a rest tremor can usually stop the tremor by making a point of moving the part of their body that shakes.

●Action tremors

– Action tremors happen when you are moving your muscles on purpose. There are a few different kinds of action tremors, including:

•Kinetic tremors

– These happen when you move on purpose, such as writing or drinking from a cup. Sometimes, the tremor gets worse gradually as you get closer to what you trying to do or reach. This is called “intention” tremor.

•Postural tremors

– These happen when you try to hold a body part still in a position other than its resting position. For example, your legs might shake when you are standing up, or your arms might shake if you hold them out in front of you.

•Isometric tremors

– These happen when you move a muscle against something that is still. For example, they might happen when you push against a wall or make a fist with your hand.

●Functional tremor

– Functional tremor can combine features of rest and action tremors. Unlike other kinds of tremor, functional tremor has no known medical cause. This kind of tremor usually gets less severe if you are distracted while your doctor examines you, for example, if he or she asks you to do something else with another part of your body. Other types of tremor tend to get worse with distraction.

What are the most common causes of rest tremor? 

— The most common cause of rest tremor is Parkinson disease. If that is the cause of your tremor, your doctor or nurse will probably focus on treating your Parkinson disease. This will hopefully help reduce your tremor.

Other problems that can cause rest tremors include diseases that damage parts of the brain, and a rare condition called Wilson disease, which causes copper to build up in the body.

What are the most common causes of action tremor? 

— The most common cause is something called a “physiologic” tremor. Everyone, even people who are healthy, has a little bit of shaking of the hands. This is what doctors refer to as “physiologic tremor.” It is normal, and you don’t usually notice it, because it is very mild. But in some cases this “physiologic” or normal tremor can become exaggerated. This can happen:

●If you take certain medicines, such as those used to treat depression, or asthma and other breathing problems

●If you drink coffee, smoke cigarettes, or use “stimulants” (including caffeine and certain medicines)

●If you are anxious, excited, or afraid

●If your muscles are very tired, for example because you just worked out

●As the effects of alcohol or other drugs are wearing off

●If you have an overactive thyroid gland

●If you have a fever

If your tremor is caused by 1 of the problems listed above, the tremor should go away as soon as the problem goes away. Of course, if your tremor is caused by a medicine, you might not be able to stop taking it. But it might be possible to switch medicines or to lower the dose.

What is essential tremor? 

— Essential tremor is a nervous system problem that causes action tremor. It is different from physiologic tremor in that it is not related to medicines, substances, or physical conditions such as fever. Essential tremor can be passed on in families.

People who have essential tremor usually shake when they try to hold their arms out straight. They also tend to shake when they move their hands with a goal in mind. For instance, their hands might shake when they try to write, drink from a glass, or touch their nose with their finger.

Essential tremor sometimes even affects the head. This makes it look as though the person is nodding their head “yes-yes” or shaking their head “no-no.”

Is there a test to find out the cause of tremor? 

— No, there is no test. But your doctor or nurse can learn about a lot about your tremor just by asking you questions and watching you move. Your doctor or nurse might send you for a brain scan or blood tests to make sure your tremor is not caused by something serious. But it’s likely that he or she will be able to tell what’s wrong just by doing an exam.

How is tremor treated? 

— If a tremor is caused by another medical problem, treating that problem – if it can be treated – sometimes helps reduce the tremor, too. For example, people whose tremor is caused by high thyroid hormone levels often stop shaking when their hormone levels go back to normal.

Even when no other medical problems are involved, there are treatments that can help. There are a few medicines that can reduce a person’s tremor. If the medicines are not effective enough and the tremor is severe, it is even possible to have a device implanted in the brain that can help control tremor.

This educational content was put together by Dr. Carlo Oller (Emergency Physician) as part of a project to accumulate quality patient education about different conditions under one website for free. You can find this, and many other educational content at

Last updated 3/3/19

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