Tremor

An involuntary, rhythmic, oscillatory muscle contraction causing shaking of one or more body parts, classified according to activation condition (rest, postural, action), distribution, and frequency.

Causes

• Neurological causes

  • Parkinson’s disease

  • Essential tremor

  • Multiple sclerosis

  • Stroke

  • Cerebellar disorders

• Withdrawal and substance-related causes

  • Alcohol withdrawal

  • Caffeine excess

  • Drug withdrawal states

• Endocrine and metabolic causes

  • Hyperthyroidism

  • Hypoglycemia

  • Liver failure

  • Kidney failure

• Medication-related causes

  • β-agonists

  • Corticosteroids

  • Psychiatric medications (e.g., antidepressants, antipsychotics, lithium)

• Toxic causes

  • Mercury

  • Lead

• Physiological causes

  • Stress

  • Anxiety

  • Muscle fatigue

  • Sleep deprivation

  • Normal enhanced physiologic tremor