Hoehn and Yahr scale
The Hoehn and Yahr scale is a simple way to describe how Parkinson’s disease symptoms progress. It was first published in 1967 by Margaret Hoehn and Melvin Yahr in Neurology and originally had five stages, from 1 to 5. A later version added stages 1.5 and 2.5 to better describe the middle stages. The scale can be used automatically, even for patients who cannot support themselves. It is part of the Unified Parkinson’s Disease Rating Scale (UPDRS), specifically UPDRS Part V, which focuses on daily activities and some non-motor symptoms in treatment planning. A 2010 study of 695 patients looked at how long it typically takes to progress through the stages, with results varying between individuals.
This page was last edited on 2 February 2026, at 05:23 (CET).