Tremors are involuntary, rhythmic muscle movements that can affect various parts of the body, most commonly the hands. They can be caused by a wide range of factors including neurological disorders, medications, metabolic conditions, and lifestyle factors.
Common Causes of Tremors
- Neurological disorders: Tremors often arise from problems in brain areas that control movement, such as the basal ganglia or cerebellum. Conditions include Parkinson’s disease, essential tremor (a neurological condition often inherited), multiple sclerosis, stroke, traumatic brain injury, and brain tumors
- Medications: Certain drugs can induce tremors, including asthma medications, corticosteroids, chemotherapy agents, antipsychotics, and some psychiatric or neurological drugs
- Metabolic and systemic conditions: Overactive thyroid (hyperthyroidism), liver or kidney failure, diabetes (especially blood sugar fluctuations), and alcohol use disorder or withdrawal can cause tremors
- Toxins: Exposure to heavy metals (mercury, lead, manganese, arsenic) and pesticides may lead to tremors
- Lifestyle and physiological factors: Stress, anxiety, fatigue, excessive caffeine intake, muscle tiredness, and normal aging can trigger or worsen tremors
- Genetics: About half of essential tremor cases have a familial (genetic) basis, inherited in an autosomal dominant pattern
Types of Tremors and Their Causes
- Resting tremor: Occurs when muscles are relaxed; often linked to Parkinson’s disease or medication effects on basal ganglia
- Intention tremor: Happens during purposeful movement; usually due to cerebellar damage from stroke, tumor, or hereditary disorders affecting coordination
- Postural tremor: Seen when holding a position against gravity; common in essential tremor and physiologic tremor
Summary
Tremors result from complex interactions of neurological, metabolic, toxic, genetic, and lifestyle factors. Some tremors are benign or physiological, while others indicate serious underlying conditions like Parkinson’s disease or brain injury. Diagnosis often requires medical history, neurological examination, and sometimes imaging or lab tests to identify the cause
. This broad range of causes explains why tremors vary widely in presentation and severity.
