What is tremor?
Tremor is an unintentional, rhythmic muscle movement involving to-and-fro movements (oscillations) of one or more parts of the body. It is the most common of all involuntary movements and can affect the hands, arms, head, face, voice, trunk, and legs. Most tremors occur in the hands.
In some people, tremor is a symptom of a neurological disorder or appears as a side effect of certain drugs. The most common form of tremor, however, occurs in otherwise largely healthy people. Although tremor is not life-threatening, it can be embarrassing to some people and make it harder to perform daily tasks.
Its rhythmic pattern is caused by unintentional (involuntary) muscle contractions. The tremor may occur at separate times with breaks in between them or be constant. Tremor can occur sporadically (on its own) or happen as a result of another disorder.
What are the characteristics of tremor? Characteristics may include a rhythmic shaking in the hands, arms, head, legs, or trunk; shaky voice; difficulty writing or drawing; or problems holding and controlling utensils, such as a fork. Some tremors may be triggered by or become exaggerated during times of stress or strong emotion, when the individual is physically exhausted, or during certain postures or movements.
Tremor may occur at any age but is most common in middle-aged and older persons. It may be occasional, temporary, or occur intermittently. Tremor affects men and women equally.
Tremor is an unintentional, rhythmic muscle movement involving to-and-fro movements (oscillations) of one or more parts of the body. It is the most common of all involuntary movements and can affect the hands, arms, head, face, voice, trunk, and legs. Most tremors occur in the hands.
In some people, tremor is a symptom of a neurological disorder or appears as a side effect of certain drugs. The most common form of tremor, however, occurs in otherwise largely healthy people. Although tremor is not life-threatening, it can be embarrassing to some people and make it harder to perform daily tasks.
Its rhythmic pattern is caused by unintentional (involuntary) muscle contractions. The tremor may occur at separate times with breaks in between them or be constant. Tremor can occur sporadically (on its own) or happen as a result of another disorder.
What are the characteristics of tremor? Characteristics may include a rhythmic shaking in the hands, arms, head, legs, or trunk; shaky voice; difficulty writing or drawing; or problems holding and controlling utensils, such as a fork. Some tremors may be triggered by or become exaggerated during times of stress or strong emotion, when the individual is physically exhausted, or during certain postures or movements.
Tremor may occur at any age but is most common in middle-aged and older persons. It may be occasional, temporary, or occur intermittently. Tremor affects men and women equally.
Tremor can be classified into two main categories: resting and action.
Resting tremor occurs when the muscle is relaxed, such as when your hands are resting on your lap. Your hands, arms, or legs may shake even when they are at rest. Often, the tremor only affects the hand or fingers. This type of tremor is often seen in people with Parkinson's disease.
Action tremor occurs with the voluntary movement of a muscle. Most types of tremor are considered action tremor. There are several sub-classifications of action tremor, many of which overlap.
Resting tremor occurs when the muscle is relaxed, such as when your hands are resting on your lap. Your hands, arms, or legs may shake even when they are at rest. Often, the tremor only affects the hand or fingers. This type of tremor is often seen in people with Parkinson's disease.
Action tremor occurs with the voluntary movement of a muscle. Most types of tremor are considered action tremor. There are several sub-classifications of action tremor, many of which overlap.
- Postural tremor occurs when you are holding a position against gravity, such as keeping your arms outstretched.
- Kinetic tremor is associated with any voluntary movement, such as moving your wrists up and down or closing and opening your eyes.
- Intention tremor starts when you make an intended movement toward a target, such as lifting a finger to touch your nose.
- Task-specific tremor only appear when you are performing highly skilled, goal-oriented tasks such as handwriting or speaking.
- Isometric tremor occurs during a voluntary muscle contraction that is not accompanied by any movement, such as when you are holding a heavy book in the same position.
Tremor is not life threatening on its own. However, it can be challenging and even disabling, making it difficult or even impossible for you to perform work and daily life tasks such as bathing, dressing, writing, and eating.
Common symptoms of tremor may include:
Tremors can be the result of:
Common symptoms of tremor may include:
- A rhythmic shaking in your hands, arms, head, legs, or torso
- A shaky voice
- Difficulty doing tasks with your hands, such as writing or drawing
- Problems holding and controlling utensils, such as a spoon, or other items
- Head-nodding
Tremors can be the result of:
- Neurological disorders, such as multiple sclerosis, stroke, or a traumatic brain injury, which affect parts of the brain that controls muscles throughout the body.
- Neurodegenerative diseases, which damage or destroy parts of the brainstem.
- Alcohol or drug abuse.
- Medication side effects.
There are more than 20 types of tremor. Some of the most common are:
Essential tremor--Essential tremor (previously also called benign essential tremor or familial tremor) is one of the most common movement disorders. Its key feature is a tremor in both hands and arms during action and when standing still. It also may affect your head and voice and how you walk. Although the tremor can start at any age it most often initially appears during adolescence or in middle age (between ages 40 and 50). It can be mild and stay the same, or slowly get worse.
The exact cause of ET is unknown. Studies show essential tremor is accompanied by a mild degeneration of the cerebellum, which is the part of your brain that controls movement. About 50 percent of the cases of essential tremor are thought to be caused by a genetic risk factor (referred to as familial tremor). Children of a parent who has familial tremor have greater risk of inheriting the condition. Familial forms of essential tremor often appear early in life.
Probable essential tremor
Dystonic tremor--Dystonic tremor occurs in people who are affected by dystonia—a movement disorder where incorrect messages from the brain cause muscles to be overactive, resulting in abnormal postures or sustained, unwanted movements. Dystonic tremor usually appears in young or middle-aged adults and can affect any muscle in the body. Symptoms may sometimes be relieved by complete relaxation or the severity may be reduced by touching the affected body part or muscle.
Cerebellar tremor--Cerebellar tremor is typically a slow, easily visible tremor of the arms, legs, hands, or feet that occurs at the end of a purposeful movement such as pressing a button. It is caused by damage to the cerebellum and its pathways to other brain regions, often from a stroke or tumor, injury from a disease or an inherited disorder, or from chronic damage due to alcoholism.
Psychogenic tremor--Psychogenic tremor (also called functional tremor) can appear as any form of tremor. Its symptoms may vary but often start and stop suddenly and may affect all body parts. The tremor increases in times of stress and decreases or disappears when you are distracted.
Physiologic tremor--Everyone has physiologic tremor. It is rarely visible to the eye and typically involves a fine shaking of both of the hands and also the fingers. It is not considered a disease but is a normal human phenomenon that is the result of physical properties in the body (for example, rhythmical activities such as heartbeat and muscle activation). Enhanced physiologic tremor is a more noticeable case of physiologic tremor that can be easily seen. It is generally not caused by a neurological disease but by reaction to certain drugs, alcohol withdrawal, or medical conditions including an overactive thyroid and hypoglycemia. It is usually reversible once the cause is corrected.
Parkinsonian tremor--Parkinsonian tremor is common and one of the first signs of Parkinson's disease, although not all people with Parkinson's disease have tremor. Its shaking is most noticeable when the hands are at rest and may look as if someone's trying to roll a pill between the thumb and a finger. Parkinson's tremor may also affect the chin, lips, face, and legs. The tremor may initially appear in only one limb or on just one side of the body but may spread to both sides as the disease progresses. The tremor is often made worse by stress or strong emotions.
Orthostatic tremor--Orthostatic tremor is a rare disorder characterized by rapid muscle contractions in the legs that occur when you stand up. The tremor is usually relieved when you sit or walk. Standing may make you feel unsteady or unbalanced, causing you to immediately try to sit or walk. Because the tremor has such a high frequency (very fast shaking) it may not be visible to the naked eye but can be felt by touching the thighs or calves or can be detected by a doctor examining the muscles with a stethoscope. In some cases, the tremor can become more severe over time. The cause of orthostatic tremor is unknown, and many doctors don't understand the condition.
Generally, tremor is caused by a problem in the deep parts of the brain that control movements. Some forms of tremor are inherited and run in families, while others have no known cause. Sometimes tremor is a symptom of another neurological disorder or a side effect of certain drugs, but the most common form occurs in otherwise healthy people. Other causes of tremor can include the use of certain medicines, alcohol use disorder or withdrawal, and an overactive thyroid. Tremor may occur at any age but is most common in middle-aged and older adults.
Essential tremor--Essential tremor (previously also called benign essential tremor or familial tremor) is one of the most common movement disorders. Its key feature is a tremor in both hands and arms during action and when standing still. It also may affect your head and voice and how you walk. Although the tremor can start at any age it most often initially appears during adolescence or in middle age (between ages 40 and 50). It can be mild and stay the same, or slowly get worse.
The exact cause of ET is unknown. Studies show essential tremor is accompanied by a mild degeneration of the cerebellum, which is the part of your brain that controls movement. About 50 percent of the cases of essential tremor are thought to be caused by a genetic risk factor (referred to as familial tremor). Children of a parent who has familial tremor have greater risk of inheriting the condition. Familial forms of essential tremor often appear early in life.
- Postural tremor of moderate amplitude is present in at least one arm
- Tremor of moderate amplitude is present in at least one arm during at least four tasks, such as pouring water, using a spoon to drink water drinking water, finger-to-nose maneuver, and drawing a spiral.
- Tremor must interfere with at least one activity of daily living.
- Medications, hypothyroidism, alcohol, and other neurological conditions are not the cause of tremor.
Probable essential tremor
- Tremor of moderate amplitude is present in at least one arm during at least four tasks, or head tremor is present.
- Medications, hyperthyroidism, alcohol, and other neurological conditions are not the cause of tremor.
Dystonic tremor--Dystonic tremor occurs in people who are affected by dystonia—a movement disorder where incorrect messages from the brain cause muscles to be overactive, resulting in abnormal postures or sustained, unwanted movements. Dystonic tremor usually appears in young or middle-aged adults and can affect any muscle in the body. Symptoms may sometimes be relieved by complete relaxation or the severity may be reduced by touching the affected body part or muscle.
Cerebellar tremor--Cerebellar tremor is typically a slow, easily visible tremor of the arms, legs, hands, or feet that occurs at the end of a purposeful movement such as pressing a button. It is caused by damage to the cerebellum and its pathways to other brain regions, often from a stroke or tumor, injury from a disease or an inherited disorder, or from chronic damage due to alcoholism.
Psychogenic tremor--Psychogenic tremor (also called functional tremor) can appear as any form of tremor. Its symptoms may vary but often start and stop suddenly and may affect all body parts. The tremor increases in times of stress and decreases or disappears when you are distracted.
Physiologic tremor--Everyone has physiologic tremor. It is rarely visible to the eye and typically involves a fine shaking of both of the hands and also the fingers. It is not considered a disease but is a normal human phenomenon that is the result of physical properties in the body (for example, rhythmical activities such as heartbeat and muscle activation). Enhanced physiologic tremor is a more noticeable case of physiologic tremor that can be easily seen. It is generally not caused by a neurological disease but by reaction to certain drugs, alcohol withdrawal, or medical conditions including an overactive thyroid and hypoglycemia. It is usually reversible once the cause is corrected.
Parkinsonian tremor--Parkinsonian tremor is common and one of the first signs of Parkinson's disease, although not all people with Parkinson's disease have tremor. Its shaking is most noticeable when the hands are at rest and may look as if someone's trying to roll a pill between the thumb and a finger. Parkinson's tremor may also affect the chin, lips, face, and legs. The tremor may initially appear in only one limb or on just one side of the body but may spread to both sides as the disease progresses. The tremor is often made worse by stress or strong emotions.
Orthostatic tremor--Orthostatic tremor is a rare disorder characterized by rapid muscle contractions in the legs that occur when you stand up. The tremor is usually relieved when you sit or walk. Standing may make you feel unsteady or unbalanced, causing you to immediately try to sit or walk. Because the tremor has such a high frequency (very fast shaking) it may not be visible to the naked eye but can be felt by touching the thighs or calves or can be detected by a doctor examining the muscles with a stethoscope. In some cases, the tremor can become more severe over time. The cause of orthostatic tremor is unknown, and many doctors don't understand the condition.
- Essential tremor usually appears on both sites of the body and is often noticed more in the dominant hand
- Dystonic tremor can affect any muscle in the body and usually is associated with abnormal body postures due to forceful muscle spasms or cramps
- Parkinsonian tremor, with shaking of one or both hands at rest and may also affect the lips, face, and legs
Generally, tremor is caused by a problem in the deep parts of the brain that control movements. Some forms of tremor are inherited and run in families, while others have no known cause. Sometimes tremor is a symptom of another neurological disorder or a side effect of certain drugs, but the most common form occurs in otherwise healthy people. Other causes of tremor can include the use of certain medicines, alcohol use disorder or withdrawal, and an overactive thyroid. Tremor may occur at any age but is most common in middle-aged and older adults.
Tremor is most commonly classified by its appearance and cause or origin. There are more than 20 types of tremor and some of the most common forms include the following:
Tremors can also be described based on their properties of amplitude and frequency.
- Amplitude means the range of motion. Think of a playground swing. If no one is in it and a wind comes up, it will be begin to sway as it dangles. In a gentle breeze it will act like a pendulum with a limited range of motion. But if a passing child walks up to it and gives it a hard push, the arc of its motion will have greater width back and forth. That’s the amplitude.
- Frequency is now many times something occurs within a specified amount of time. The faster the motion of the swing, the more times per minute it will swing from one end to another.
When you think about the variations that can occur with tremors, it’s clear that diagnosing the underlying condition or disease may be somewhere between a science and an art. Even when a neurologist has diagnosed a person as having ET, one person’s ET is not identical with another’s. There is much room for variation.
How are tremors diagnosed?
Tremors aren’t always serious, but they may sometimes indicate a serious disorder. They’re often part of medical disorders that affect the brain, nervous system, or muscles.
Contact a doctor if you develop unexplained tremors.
Physical exam
During a physical exam, your doctor will observe the affected area. Tremors are apparent upon visual inspection. However, the cause of the tremor can’t be diagnosed until the doctor performs further tests.
Your doctor may also request that you write or hold an object to evaluate the severity of your tremor.
Laboratory tests
Your doctor may collect blood and urine samples to check for signs of thyroid disease or other medical conditions.
Neurological tests
Your doctor may perform a neurological exam too. This exam will check the functioning of your nervous system. It will measure your:
Tremors aren’t always serious, but they may sometimes indicate a serious disorder. They’re often part of medical disorders that affect the brain, nervous system, or muscles.
Contact a doctor if you develop unexplained tremors.
Physical exam
During a physical exam, your doctor will observe the affected area. Tremors are apparent upon visual inspection. However, the cause of the tremor can’t be diagnosed until the doctor performs further tests.
Your doctor may also request that you write or hold an object to evaluate the severity of your tremor.
Laboratory tests
Your doctor may collect blood and urine samples to check for signs of thyroid disease or other medical conditions.
Neurological tests
Your doctor may perform a neurological exam too. This exam will check the functioning of your nervous system. It will measure your:
- tendon reflexes
- coordination
- posture
- muscle strength
- muscle tone
- ability to feel touch
- During the exam, you may need to:
- touch your finger to your nose
- draw a spiral
- perform other tasks or exercises
There’s no cure for essential tremor, but there are ways to treat it.
The main treatment options are medications, assistive devices, botulinum toxin, deep brain stimulation and focused ultrasound.
The main treatment options are medications, assistive devices, botulinum toxin, deep brain stimulation and focused ultrasound.
- Medication:
- Adaptive devices:
- Botulinum toxin: This involves injection into the tremoring muscles to temporarily weaken the muscles and lessen tremor severity.
- Deep brain stimulation:
- Focused ultrasound: