What is Parkinson's disease?

Parkinson's disease (PD) is a neurological condition that typically causes tremor and/or stiffness in movement. The condition affects about 1 to 2 percent of people over the age of 60 years and the chance of developing PD increases as we age. Most people affected with PD are not aware of any relatives with the condition but in a number of families, there is a family history. When three or more people are affected in a family, especially if they are diagnosed at an early age (under 50 years) we suspect that there may be a gene making this family more likely to develop the condition.