Are hand tremors a bad sign? Here’s what the science says.

But as we get older, the frequency of our normal background tremor becomes slower and may become more noticeable in everyday activities. Around a quarter of people over the age of 70 have some form of visible tremor.

There are also potential triggers that can enhance our baseline tremor to the point it can be detected by the naked eye. These include:

• Extreme fear, anxiety or fatigue.
• Fever, hyperthyroidism or low blood sugar.
• Vigorous exercise.
• Alcohol and opioid withdrawal.
• Certain drugs, such as anti-depressants like SSRIs or SNRIs, albuterol, prednisone, nicotine and caffeine.

In these situations, addressing the potential triggers can fix the apparent tremor.

However, there are some important times when a tremor is a sign of an underlying condition such as Parkinson’s disease or multiple sclerosis. If you have a new tremor with no obvious trigger, talk to your doctor.

Underlying causes of tremors

Tremors are involuntary movements usually due to quick, alternating contractions of antagonistic muscles — your biceps and triceps, for example — in which one of the pair relaxes while the other contracts to move part of your body.

Beyond what we know about the role of the brain and muscles in tremors, there is long-standing evidence that the gut plays an important role in many neurological disorders. Recently, scientists have found that people with Parkinson’s disease and essential tremor have unique changes in their microbiomes, and tremor severity is correlated with changes in certain short-chain fatty acids, beneficial compounds that are produced when bacteria in our colons ferment fiber.

The first question a physician may ask about your tremor is whether it happens while at rest, like while your arm is otherwise comfortably supported on a chair, or during voluntary activity. In some cases where the cause of your tremor is unclear, doctors may order a special head scan.

Potential causes of tremors

Maybe your tremor occurs more with action — or seems to happen only when writing (known as a primary writing tremor). You may have an essential tremor, which is very common.

Patients with essential tremor describe scenarios like trying to type on a keyboard and accidentally hitting the same key over and over, trouble holding their hands steady to shave or frustration with food falling off theirs fork before it can reach their mouths.

Essential tremors can run in families and often happens symmetrically to both hands. It may even transiently improve with alcohol because of ethanol’s effect on receptors in the cerebellum and brainstem.

But while alcohol may alleviate the tremor briefly, it frequently causes a rebound shortly after ingestion with an increased tremor amplitude that can last several hours. And besides the concerns of alcohol-use disorder, long-standing alcohol use may further compromise the same neural pathways responsible for the tremor in the first place.

Instead, there are several options to treat an essential tremor that your doctor can advise you on: drugs like propranolol and primidone, wearing weighted gloves or even deep brain stimulation.

Essential tremor is not considered dangerous per se, but some people appear to be at higher risk of ultimately developing Parkinson’s disease, so keeping your doctor in the loop about any health changes is important.

Essential tremors are more common as we get older, and some studies found that a new tremor occurring after the age of 65 is associated with a risk of dementia.

Tremor is the first symptom in roughly 3 out of 4 people with Parkinson’s disease. In Parkinson’s disease, the tremor often starts in just one hand while at rest (sometimes appearing as if the thumb and forefinger are “rolling a pill” back and forth), but may also occur in the leg or foot.

This tremor is linked in part to dopamine depletion in an area of the brain called the substantia nigra. Parkinson’s disease patients may benefit from medications that boost their body’s supply of dopamine, like levodopa.

Tremor affects many patients with multiple sclerosis, an immune-related disease of the central nervous system. People with multiple sclerosis may experience “attacks” of neurological symptoms, like sudden loss of sensation on one side or trouble with their vision, that seem to improve on their own before another episode begins.

A less common cause of tremor, Wilson’s disease, is more frequently diagnosed in younger patients and occurs due to a genetic defect causing copper to accumulate in parts of the body, like the liver, joints and brain.

What I want my patients to know

Many people find their tremor embarrassing and disruptive to their ability to do everyday tasks like brushing teeth and eating — much less doing their jobs or hobbies they love. People with movement disorders may benefit from a broader health care team beyond just their doctor or may have needs that go beyond a prescription. Make sure to ask how you can become connected to other specialists — like physical and occupational therapists, psychologists or dietitians — who can help improve your overall health and wellness.

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