What is a Tremor?
A tremor is a rhythmic, involuntary movement in the body affecting the arms, legs, neck, tongue, chin, or vocal cords, with hand tremors being the most common. Tremors are often a symptom of a neurological disorder, although many other factors can cause them.
While not life-threatening, tremors can be embarrassing and debilitating. Shaking hands and body tremors make everyday tasks more difficult. A tremor can start at any age, although they are more common in middle-aged and older adults.
Types of Tremors
There are over 20 types of tremors. They are typically defined by their origin, cause, and appearance. The most common types of tremors include:
- Essential tremor. Formerly called benign essential tremor, this type of tremor is the most common movement disorder. Primary symptoms include uncontrolled shaking, a quivering voice, a nodding “yes-yes” or “no-no” of the head, and, in extreme cases, balance issues.
- Dystonic tremor. Dystonic tremor occurs in people with dystonia, a condition in which uncontrollable muscle contractions cause abnormal postures or repetitive movements, such as twisting of the neck.
- Cerebellar tremor. This type of tremor is caused by lesions or damage to the cerebellum (which helps maintain balance and posture) from a stroke or a tumor. Manifesting in the arms, legs, and other extremities, cerebellar tremors can directly affect a person’s balance.
- Functional tremor. Previously referred to as psychogenic tremor, this tremor is defined by its sudden onset and abatement of uncontrollable shaking. Physical injury, medication side effects, or panic attacks are usually the cause, not a neurological disorder.
- Physiologic tremor. This kind of tremor is slight, sometimes imperceptible to the eye. It presents as a small shaking in both hands and the fingers. It is a normal result of the heartbeat and bodily muscle activity and is not a symptom of a disease.
- Enhanced physiologic tremor. This type of tremor is a more visible version of physiologic tremor, typically caused by alcohol withdrawal, drug reactions, an overactive thyroid, or hypoglycemia.
- Orthostatic tremor. This is a rare disorder in which the leg muscles rapidly contract when standing, causing unsteadiness or imbalance.
Classifications of Tremors
Tremors are classified into two categories: resting tremor and acting tremor.
- Resting tremors occur when a person is lying down or sitting, usually only in the hands. The tremor stops when the individual starts moving around.
- Acting tremors happen when a person is moving the affected body part.
Acting tremors are broken down into the following subcategories:
- Postural tremor. Postural tremor occurs when an extremity is pitted against gravity, as when holding an arm or a leg in the air.
- Kinetic tremor. Kinetic tremor appears when you voluntarily move a body part such as opening and closing the eyes, or moving your wrist up and down.
- Intention tremor. Intention tremor happens during intentional, targeted movements, such as touching your finger to your nose.
- Task-specific tremor. A task-specific tremor occurs while executing specific tasks, such as playing the piano, knitting, or drawing.
- Isometric tremor. Isometric tremor appears when you purposefully contract your muscles but keep the body part still, such as when making a fist.
Signs & Symptoms of Tremors
The signs of tremor can be unmistakable or unseen, depending on the classification and type.
Some common symptoms of tremors include:
- Rhythmic shaking in the head, hands, arms, legs, or torso
- Difficulty with physical tasks such as writing, sewing, or drawing
- Shaky voice, causing quavering when speaking
- Difficulty holding or controlling things, such as eating utensils or razors
What Causes Tremors?
Some causes of tremors can be linked to various neurological disorders or conditions. Other causes can develop due to lifestyle behaviors or sudden trauma, such as a stroke or head injury.
Medical causes of tremors can include:
- Parkinson’s disease
- Traumatic brain injury (TBI)
- Multiple sclerosis (MS)
- Alcohol abuse
Other causes of tremors can include:
- Muscle fatigue
- Too much caffeine
- Low blood sugar
- Reaction to prescription medications
The underlying cause of some tremors can remain unknown. Tremors can go away on their own.
Risk Factors for Tremors
Anyone at any age can develop a tremor, but there are genetic, environmental, and behavioral factors that can increase a person’s risk of developing one.
Risk factors for tremors include:
- Altered gene. In the case of a familial tremor (a type of essential tremor), patients may have inherited a gene for the disorder. It only takes one parent with the gene to pass on the condition, giving children a 50 percent chance of having it.
- Age. Tremors usually develop in middle-aged and elderly adults.
- Heavy alcohol use. In particular, tremors may occur when one stops drinking abruptly and experiences withdrawals.
While there is no known way to completely prevent a tremor, there are things you can do to reduce the chances of occurrence or provide relief from trembling hands and body shakes.
- Lifestyle changes. Avoiding or reducing your caffeine and alcohol intake can reduce the possibility or severity of tremors. Lowering your stress levels, such as through exercise or meditation, can also help.
- Physical adjustments. By changing the way you do everyday tasks, you can avoid the possibility of uncontrollable shaking. For example, if you’ve experienced hand tremors, try dictating texts instead of typing.
Trust NewYork-Presbyterian for Tremor Care
The world-renowned specialists at NewYork-Presbyterian continually conduct clinical research to learn more about the causes of tremors and other neurological conditions and disorders. Our team is here to offer an expert diagnosis and provide cutting-edge solutions to manage your symptoms.
If you are experiencing a tremor or any other type of movement disorder, contact us to make an appointment and get started on a personalized treatment plan.