Trembling

Trembling is the involuntary, rhythmic shaking of one or more parts of the body. This symptom—which is technically referred to as tremors—can occur temporarily (such as after you've had a lot of caffeine) or as part of an underlying health condition. Tremors most commonly affect the hands but can also affect the legs, head, trunk, or vocal cords. Though tremors aren't dangerous, they can significantly impact your quality of life.

This article discusses trembling—what can cause this symptom, treatment for underlying causes, and how trembling is diagnosed.

Symptoms of Trembling

The main symptom of trembling (or tremors) is involuntary shaking. Symptoms can be constant or come and go, depending on the underlying cause. For this reason, tremors are categorized as resting or active.

Tremors that occur when the muscles are relaxed are called resting tremors. These typically show up as shaking hands, arms, or legs.

For example, Parkinson's disease causes a resting tremor that affects the fingers. This is sometimes called a pill-rolling tremor because the movement of the fingers looks as if a person is rolling a small object between their fingers.

Active tremors occur when a person is trying to perform a task, contracting the muscles purposefully. There are multiple types of active tremors, including the following:

• Intention tremor: This occurs when someone tries to touch a specific object with a finger.
• Postural tremor: Trembling occurs when a person tries to stay in a static position, such as holding their arms overhead.
• Kinetic tremor: This type of trembling can occur with any voluntary movement, such as moving a joint back and forth or blinking.
• Task-specific tremors: Trembling occurs during higher-level tasks, such as speaking or writing.
• Isometric tremor: This tremor causes shaking when someone holds an object in one position without moving.

Tremors are also classified into different types, which produce varying trembling symptoms. These include:

• Essential tremor: This active tremor typically causes trembling in the arms and hands, both at rest and during movement. It is the most common type of movement disorder, but its cause is unknown.
• Dystonic tremor: This tremor occurs with a specific condition called dystonia. Trembling tends to be jerky rather than rhythmic.
• Cerebellar tremor: Trembling occurs with damage to the cerebellum and usually occurs at the end of a specific movement when performing a functional task.
• Psychogenic tremor: This type of tremor can be brought on by stress and usually decreases when a person is distracted. It often occurs with underlying psychiatric conditions.
• Enhanced physiologic tremor: This trembling is temporary and associated with hypoglycemia (low blood sugar), hyperthyroidism (overactive thyroid), alcohol withdrawal, and certain drug use.
• Orthostatic tremor: This causes leg trembling but only when standing. However, the cause of this type of tremor is not known.

Causes of Trembling

Trembling can occur temporarily or long term. In addition to body shakes, trembling can also affect the voice.

Temporary trembling can result from:

• Caffeine intake
• Substance abuse
• Alcohol withdrawal
• Overactive thyroid
• Mercury poisoning
• High levels of anxiety
• Kidney failure
• Liver failure
• Fever
• Exhaustion
• Low blood sugar

Trembling can also result from neurological diseases. Examples include:

• Parkinson's disease
• Dystonia
• Peripheral neuropathy
• Chronic inflammatory demyelinating polyneuropathy (CIDP)
• Functional neurologic disorder
• Traumatic brain injury
• Multiple sclerosis (MS)
  

How to Treat Trembling

Treatment for trembling depends on the underlying cause. In some situations—such as excessive caffeine intake or alcohol withdrawal—symptoms can resolve on their own.

Trembling caused by medications can sometimes be treated by switching to a different medication. However, this is a decision that your healthcare provider needs to make. Sometimes, the benefits of a particular drug outweigh the uncomfortable side effects.

Tremors caused by other health issues often resolve when the underlying condition is treated—such as low blood sugar, overactive thyroid, fever, and substance abuse.

If tremors are occurring because of a condition that cannot be treated, certain medications can help reduce trembling. These include:

• Beta-blockers (propranolol, metoprolol, sotalol, atenolol, nadolol)
• Benzodiazepines (clonazepam, alprazolam)
• Botox injection
• Neurontin (gabapentin)

For more severe cases, trembling can be treated with deep brain stimulation (DBS).

Are There Tests to Diagnose Trembling?

Your healthcare provider can identify tremors by asking questions and observing your symptoms. In some cases, they can easily determine the underlying cause by reviewing your lifestyle habits (such as substance use) and medications. However, diagnosing underlying health conditions requires additional testing.

Blood work is often done as one of the first steps in diagnosing conditions that can cause tremors. Imaging is also performed to help diagnose neurological diseases that can cause trembling.

Examples include:

• X-rays
• Ultrasound
• Magnetic resonance imaging (MRI)
• Computed tomography (CT scan)
• Positron emission tomography (PET scan)

Summary

Trembling, or tremors, is the involuntary shaking of body parts, often in the hands. Though it is generally harmless, it can interfere with your quality of life and may signify an underlying health condition. Many types of tremors cause trembling and result from various circumstances and conditions, including excessive caffeine consumption, substance use and withdrawal, anxiety, neurodegenerative diseases, and more.

Your healthcare provider can often diagnose trembling by asking questions and observing your symptoms. However, if an underlying condition is suspected, they will likely run a series of tests to diagnose the cause. Sometimes, the trembling goes away on its own, but if treatment is required, it may include medication to treat the underlying condition or to reduce the trembling.

A Word From Verywell

Trembling can occur for various reasons—some causes are harmless, while others can be serious health conditions. Discuss your symptoms with your healthcare provider. You might be referred to a specialist, such as a neurologist, to aid in the diagnosis of the cause of your trembling.