What causes uncontrollable shaking

Overview

Uncontrollable shaking, medically referred to as tremors, is an involuntary movement characterized by rhythmic oscillations of a body part. These tremors can affect various parts of the body, most commonly the hands, but also the head, voice, trunk, and legs. While often associated with aging, tremors are not a normal part of growing older and can significantly impact a person's quality of life, affecting activities such as eating, drinking, writing, and speaking. Understanding the potential causes is the first step toward diagnosis and management.

What are the different types of tremors?

Tremors are broadly categorized based on when they occur and what triggers them. The most common types include:

• Essential Tremor: This is the most prevalent type of tremor, often appearing during voluntary movements. It typically affects the hands, and can also involve the head, voice, and legs. While it can begin at any age, it's more common in middle-aged and older adults. Essential tremor is progressive, meaning it can worsen over time. It's often inherited, with about 50% of cases having a family history.
• Parkinsonian Tremor: This tremor is characteristic of Parkinson's disease, a neurodegenerative disorder. It typically occurs at rest (resting tremor), often starting in one limb, usually a hand or finger, and can have a "pill-rolling" quality. The tremor may lessen or disappear with intentional movement but can reappear when the limb is at rest.
• Physiological Tremor: All individuals have a normal, subtle physiological tremor that is usually not visible. However, this tremor can become more pronounced and noticeable under certain conditions, such as stress, anxiety, fatigue, or the influence of certain substances like caffeine or medications.
• Dystonic Tremor: This tremor is associated with dystonia, a movement disorder characterized by involuntary muscle contractions that cause twisting and repetitive movements or abnormal postures. The tremor may occur during voluntary movement or at rest and is often accompanied by the abnormal posture of the affected body part.
• Cerebellar Tremor: Damage to the cerebellum, the part of the brain that controls coordination, can lead to a cerebellar tremor. This tremor is typically an intention tremor, meaning it worsens as a limb approaches a target during a voluntary movement. It may also be accompanied by other coordination problems.

What are the common causes of uncontrollable shaking?

The causes of uncontrollable shaking are diverse and can be linked to various medical conditions, lifestyle factors, and environmental influences:

Neurological Conditions:

Several neurological disorders can manifest with tremors:

• Essential Tremor: As mentioned, this is a primary neurological condition, often genetic, that causes rhythmic shaking, usually in the hands.
• Parkinson's Disease: This progressive disorder affects the nervous system, leading to symptoms like tremors, rigidity, slow movement, and postural instability. The tremor is a hallmark symptom, especially in the early stages.
• Multiple Sclerosis (MS): MS is an autoimmune disease that affects the central nervous system. Tremors, particularly intention tremors, can be a symptom as nerve pathways controlling movement are damaged.
• Stroke: Damage to brain areas that control movement, such as the cerebellum or basal ganglia, following a stroke can result in tremors.
• Brain Injury: Traumatic brain injuries (TBIs) can disrupt neural pathways, leading to various movement disorders, including tremors.

Metabolic and Endocrine Issues:

Imbalances in the body's chemistry can trigger tremors:

• Hyperthyroidism: An overactive thyroid gland produces excessive thyroid hormones, which can speed up the body's metabolism and lead to a fine, rapid tremor, often in the hands.
• Hypoglycemia: Low blood sugar levels can cause symptoms like shaking, sweating, and confusion.
• Liver or Kidney Failure: In severe cases, the buildup of toxins in the body due to organ failure can affect the nervous system and cause tremors.

Medication Side Effects:

Many medications can cause tremors as a side effect. These include:

• Certain asthma medications (e.g., albuterol, terbutaline)
• Antidepressants
• Mood-stabilizing drugs
• Antipsychotics
• Stimulants used to treat ADHD
• Corticosteroids
• Thyroid medication (if dosage is too high)

Substance Use and Withdrawal:

The use of or withdrawal from certain substances can induce shaking:

• Caffeine: Excessive consumption of caffeine can exacerbate physiological tremors.
• Alcohol: While moderate alcohol consumption might temporarily reduce tremors in some individuals (especially those with essential tremor), alcohol withdrawal is a common cause of significant shaking.
• Drug Withdrawal: Withdrawal from opioids, benzodiazepines, and other addictive substances can trigger tremors.

Psychological Factors:

Emotional states can significantly influence tremors:

• Stress and Anxiety: High levels of stress or anxiety can intensify physiological tremors, making them more noticeable.
• Panic Attacks: During a panic attack, a person may experience intense shaking due to the body's fight-or-flight response.

Other Causes:

• Fatigue: Extreme tiredness can worsen existing tremors or make physiological tremors more apparent.
• Aging: While not a direct cause, the likelihood of developing certain tremor types, like essential tremor, increases with age.
• Nutritional Deficiencies: Deficiencies in certain vitamins, such as vitamin B12, can sometimes be linked to neurological symptoms including tremors.

When to seek medical attention

It is important to consult a healthcare professional if you experience new or worsening uncontrollable shaking. A doctor can help determine the underlying cause through a physical examination, neurological assessment, and potentially blood tests or imaging studies. Early diagnosis and appropriate treatment can manage symptoms and improve your quality of life.