what are the stages in parkinson disease?
Hoehn and Yahr stages follow a simple rating scale, first introduced in 1967. Clinicians use it to describe how motor symptoms progress in PD. Rates symptoms on a scale of 1 to 5. On this scale, 1 and 2 represent early-stage, 2 and 3 mid-stage, and 4 and 5 advanced-stage Parkinson's.