U.S. National Library of Medicine, more than 1 million people in North America and more than 4 million people worldwide have Parkinson’s disease.
In the United States, about 60,000 people receive a diagnosis each year. Around 15% of people with the disease have a family history of Parkinson’s, which suggests they inherited genes that increased their risk of developing the condition.
However, most cases result from a complex, poorly understood interaction of genetic and environmental factors.Several environmental factors, such as head trauma, chemicals, and drugs, have associations with increased risk, whereas exercise has associations with reduced risk.