Understanding Parkinson’s
What the disease is and what is known about it: causes, the signs that come first, how it is diagnosed, and how it moves.
Is Parkinson's hereditary?
Family history is the single strongest known risk factor for Parkinson's. It is also, for most people, a small absolute risk. Both of those are true, and the gap between them is where most of the confusion lives.
What comes before Parkinson's, and how many years before
The usual article gives you ten early signs as a checklist. One study followed people through the years before diagnosis and put the signs in order — which is a more useful thing to know, and a more unsettling one.