In most cases, the stages of Parkinson’s disease (PD) progress slowly, sometimes over a period of 20 years or longer. For others, it develops quickly. Doctors commonly use the Hoehn and Yahr scale and the Unified Parkinson’s Disease Rating Scale (UPDRS) to define how PD progresses.
The Hoehn and Yahr scale classifies five stages of Parkinson’s disease:
- Stage 1 – symptoms appear on one side of the body
- Stage 2 – symptoms extend to both sides of the body, but balance remains good
- Stage 3 – the patient become physically dependent and balance is impaired
- Stage 4 – the person can walk or stand unassisted but otherwise exhibits increasing disability
- Stage 5 – requires complete assistance and is bound to a wheelchair or is bedridden
The more complex Unified Parkinson’s Disease Rating Scale (UPDRS) measures a number of factors such as mood, behavior and mental capability; muscle function; and the ability to handle activities of daily living (eating, dressing, and bathing).