What causes tremor?

A tremor is an involuntary, rhythmic movement. It may appear when a hand is resting, holding an object, reaching for something, or performing a precise task. Anxiety, lack of sleep, exertion, excess caffeine, and some medicines can make normal muscle movement more noticeable.

Other possible causes include alcohol withdrawal, low blood sugar, an overactive thyroid, nerve disorders, and movement disorders. Tremor is a symptom rather than a diagnosis, so its pattern, timing, body location, and accompanying symptoms help guide assessment.

Record when the tremor occurs, what you were doing, whether it affects one or both sides, and any triggers such as caffeine, missed meals, stress, or a new medicine. Do not stop prescribed medicine suddenly without advice. Regular meals, sleep, hydration, and reducing caffeine may help when those factors are contributing.

Arrange a medical review if the tremor persists, interferes with writing, eating, walking, or work, or comes with weakness, stiffness, balance changes, or altered speech. A clinician may review medicines and check blood glucose or thyroid function.

Seek emergency help if shaking begins suddenly with facial drooping, one-sided weakness, trouble speaking, severe confusion, loss of consciousness, or a severe headache. Seek prompt care for tremor after stopping heavy alcohol use, particularly if sweating, agitation, hallucinations, or seizures occur.

Ask: Could a medicine or withdrawal be causing this? Should my blood sugar or thyroid be checked? Does the tremor pattern suggest a neurological problem? What treatment or referral is appropriate?