What Is a Tremor?
A tremor is
an unintentional and uncontrollable rhythmic movement of one part or one limb of
your body. A tremor can occur in any part of the body and at any time. It’s
usually the result of a problem in the part of your brain that controls muscular
movement. Tremors are not always serious, but in some cases they may indicate a
serious disorder. Most tremors can’t be treated easily, but they will often go
away on their own.
It’s important to note that muscle spasms, muscle twitches, and
tremors are not the same thing. A muscle spasm is the involuntary contraction
of a muscle. A muscle twitch is an uncontrolled fine movement of a small portion
of a larger muscle. This twitch may be visible under the skin.
Types of Tremors
Tremors are divided into two types: resting and action.
Resting tremors occur
when you’re sitting or lying still. Once you begin to move around, you’ll
notice that the tremor goes away. Resting tremors often affect only the hands
Action tremors occur
during movement of the affected body part. Action tremors are further divided
- An intention
tremor occurs during targeted movement, such as touching your
finger to your nose.
- A postural
tremor occurs when holding a position against gravity, such as
holding your arm or leg outstretched.
tremors occur during a specific activity, such as writing.
tremors occur during movement of a body part, such as moving your
wrist up and down.
tremors occur during the voluntary contraction of a muscle without
other movement of the muscle.
Categories of Tremor
In addition to type, tremors are also classified by their
appearance and cause.
Essential tremor is
the most common type of movement disorder. Essential tremors are usually
postural or intention tremors. An essential tremor may be mild and not
progress, or it may slowly progress. If the essential tremor progresses, it often
starts on one side and then affects both sides within a few years.
Essential tremors weren’t thought to be associated with any
disease processes. However, recent studies have connected them to mild degeneration
in the cerebellum, which is the part of the brain that controls motor movement.
Essential tremors are sometimes associated with mild walking difficulty and
hearing disability, and they tend to run in families.
tremor is usually a resting tremor and is often the first sign of
Parkinson’s disease. It’s caused by damage to parts of the brain that control
movement. The onset is usually after age 60. It begins in one limb or on one
side of the body, and then it progresses to the other side.
A dystonic tremor occurs
irregularly. Complete rest can relieve these tremors. This tremor occurs in
people who have dystonia, which is a movement disorder characterized by involuntary
muscle contractions. The muscle contractions cause twisting and repetitive
motions or abnormal postures, such as twisting of the neck. These can occur at
The cerebellum is the part of the hindbrain that controls
movement and balance. A cerebellar
tremor is a type of intention tremor caused by lesions or damage to
the cerebellum from a stroke, tumor, or disease, such as multiple sclerosis. It
may also be the result of chronic alcoholism or overuse of certain medications.
tremor may present as any of the tremor types. It’s characterized
by sudden onset and remission, changes in the direction of your tremor and the affected
body part, and greatly decreased activity when you’re distracted. Patients with
psychogenic tremors often have conversion disorder (a psychological condition that
produces physical symptoms) or another psychiatric disease.
An orthostatic tremor usually
occurs in the legs. This is a rapid, rhythmic muscle contraction that occurs
immediately after you stand. This tremor is often perceived as unsteadiness.
There are no other clinical signs or symptoms. The unsteadiness stops when you
sit, are lifted, or when you start walking.
A physiologic tremor is
often caused by a reaction to certain drugs, alcohol withdrawal, or medical
conditions, such as hypoglycemia (low blood sugar) or an overactive thyroid
gland. Physiologic tremor usually goes away if you eliminate the cause.
What Causes Tremors to Develop?
Prescription medications, diseases, injuries, stress, and
caffeine can all cause tremors.
The most common causes of tremors are:
- muscle fatigue
- ingesting too much caffeine
- low blood sugar levels
Medical conditions that can cause tremors include:
- traumatic brain injury
- Parkinson’s disease, which is a degenerative
disease caused by loss of dopamine-producing brain cells
- multiple sclerosis, which is a condition in
which your immune system attacks your brain and spinal cord
- hyperthyroidism, which is a condition in which
your body produces too much thyroid hormone
How Are Tremors Diagnosed?
Sometimes, tremors are considered normal. When you’re under a lot
of stress or experiencing anxiety or fear, tremors may occur. Once the feeling
subsides, the tremor usually stops. Tremors are also often part of medical
disorders that affect the brain, nervous system, or muscles.
You should see your doctor if you develop unexplained tremors.
During a physical examination, the doctor will observe the
affected area. Tremors are apparent upon visual inspection. However, the cause
of the tremor can’t be diagnosed until your doctor performs further tests. Your
doctor may request that you write or hold an object to evaluate the severity of
your tremor. Your doctor may also collect blood and urine samples to check for
signs of thyroid disease or other medical conditions.
The doctor may order a neurological exam. This exam will check the functioning of your
nervous system. It will measure your tendon reflexes, coordination, posture,
muscle strength, muscle tone, and ability to feel touch. During the exam, you
may need to touch your finger to your nose, draw a spiral, or perform other
tasks or exercises.
Your doctor may also order an electromyogram, or EMG. This test measures involuntary muscle
activity and muscle response to nerve stimulation.
How Are Tremors Treated?
If you get treatment for the underlying condition causing the
tremor, that treatment may be enough to cure it. Treatments for tremor include:
There are some medications that are commonly used to treat the
tremor itself. Your doctor may prescribe them for you.
- Beta blockers are usually used to treat people
with high blood pressure or heart disease. However, they have been shown to
reduce tremors in some people.
- Tranquilizers, such as alprazolam (Xanax), may
relieve tremors that are triggered by anxiety.
- Anti-seizure medications are sometimes prescribed
for people who cannot take beta blockers or who have tremors that are not
helped by beta blockers.
Botox injections may
also relieve tremors. These chemical injections are often given to people who
have tremors that affect the face and head.
Physical therapy may
help strengthen your muscles and improve your coordination. The use of wrist
weights and adaptive devices, such as heavier utensils, may also help relieve
Brain Stimulation Surgery
Brain stimulation surgery
may be the only option for those with debilitating tremors. During this
operation, the surgeon inserts an electrical probe into the portion of your
brain responsible for the tremors. Once the probe is in place, a wire feeds from
the probe into your chest, under your skin. The surgeon places a small device
in your chest and attaches the wire to it. This device sends pulses to the
probe to stop the brain from producing tremors.