People with Parkinson's disease have a progressive loss of function of the nerve cells in the part of the brain that controls muscle movement.
Tremors occur as a result of damage to the nerve cells.
The tremor may affect one side of the body more than the other, and can affect the lower jaw, arms and legs. Other symptoms of Parkinson's disease include nightmares, depression, excess saliva, difficulty turning over in bed and buttoning clothes or cutting food, and problems with walking. No blood tests can detect Parkinson's disease. Some kinds of x-rays can help your doctor make sure nothing else is causing your symptoms. But x-rays can't show whether a person has Parkinson's disease.