brain, spinal cord, and nerve disorders
Tremor
Key Points
Tremors can be classified based on when they occur—whether at rest (resting tremor) or when moving (action tremor)—and action tremors can be classified as those occurring at the end of a movement toward a target or during any voluntary movement (kinetic tremor), when moving toward a target (intention tremor), or when holding a limb outstretched (postural tremor). Most tremors are physiologic (normal) tremors, and some are essential tremor or are caused by other disorders. Tremors that occur during rest are often caused by Parkinson disease. Doctors can usually identify the cause based on the history and physical examination. If a tremor begins suddenly or is accompanied by other neurologic symptoms, people should see a doctor right away. If people are under 50, have a tremor, but do not have a family history of essential tremors, they should see a doctor soon. The cause of the tremor is treated if possible, but otherwise, some simple strategies (such as avoiding circumstances that trigger tremors) and sometimes drugs can help control the tremors. 