Essential tremor is differentiated from the tremors caused by Parkinson's disease by the timing of the tremor, associated conditions and the parts of the body affected, according to Mayo Clinic. Symptoms of essential tremor occur gradually and worsen with movement, usually affecting the hands and sometimes the head.
Generally, essential tremors affect the head, hands and voice. The tremor is first noticeable when a person moves his hands. The tremor can also cause the head to repeatedly move up and down or from side to side, explains Mayo Clinic. The condition does not usually cause any other health problems, although it can occur with other neurological problems. In contrast, tremors caused by Parkinson's disease affect other areas of the body, including the legs and chin. The tremors start in the hands but are noticeable even when the person keeps his hands still. Tremors from Parkinson's disease are usually linked to slow movement, changes in posture and a shuffling walk.
Some people have a genetic mutation that puts them at risk for developing essential tremor, but the condition is most commonly seen in people over age 40, notes Mayo Clinic. Nearly half of all people with essential tremor developed the condition because of the genetic mutation. In other people, essential tremor develops because of changes in the brain.