
Parkinson’s Disease development is categorized using a few staging schemes. The Hoehn and Yahr Stages and the Unified Parkinson’s Disease Rating Scale (UPDRS) are the two most well-known staging systems.
In 1967, Hoehn and Yahr defined five stages of Parkinson’s Disease based on the degree of clinical dysfunction. Clinicians use it to chart the course of motor symptoms in Parkinson’s disease.