Symptoms:

Tremors may affect the hands, arms, head, eyelids, voice box, or other muscles. They rarely affect the legs or feet.

The shaking usually involves small, rapid movements -- more than 5 times a second.

The tremors may:

• Occur when you move (action-related tremor), and may be less noticeable with rest
• Come and go, but generally get worse as you age
• Disappear with sleep
• Get worse with stress, caffeine, and certain medications
• Not affect both sides of the body the same way

Head nodding may be a symptom of a tremor.

If the tremor affects the voice box, you may have a shaking or quivering sound to your voice.

Signs and tests:

Your doctor can make the diagnosis by performing a physical exam and asking questions about your medical and personal history.

A physical exam will show shaking with movement. There are usually no other problems with coordination or changes in thinking or brain function.

The quality of the tremor is often the most helpful thing in determining the cause. What parts of the body are affected? Does it happen at rest, when moving or both? How fast, and how obvious is it?

Further tests may be needed to rule out other reasons for the tremors. Blood tests and imaging studies (such as a CT scan of the head, brain MRI, and x-rays) are usually normal.