What Is Parkinson's Disease?

Northwestern Medicine treats Parkinson's Disease.Parkinson's disease is a progressive degenerative disorder that affects nerve cells, or neurons, in the part of the brain that controls movement. In Parkinson's disease, a certain group of nerve cells in the brain that produce the chemical dopamine degenerate.

The lack of dopamine causes the primary symptoms of Parkinson's disease—tremor, slowness of movement, muscle stiffness and balance problems.

More than one million (and perhaps as many as 1.5 million) people in the United States have Parkinson's disease. Here are some facts about Parkinson’s disease:

  • It affects 1 in 100 Americans over the age of 60.
  • The average age of onset is 65.
  • As many as 5 to 10 percent of people are diagnosed prior to age 40 with young-onset Parkinson's.
  • It affects slightly more men than women.
  • Early symptoms are subtle, and people may think their symptoms are "normal aging".