Parkinson's Disease

Parkinson disease (PD) is a common disorder that affects the brain's ability to control movement. PD progressively worsens over time, although the rate of worsening varies greatly from one person to another.

Tremor — Tremors (shaking) caused by PD are most noticeable when the affected body part is at rest. The tremor of early PD is intermittent and may not be noticeable to others; When the tremor becomes noticeable, it usually occurs in one hand, often described as "pill-rolling." The majority of people with PD will notice a tremor at some point in the disease, though some do not.

Bradykinesia — Bradykinesia is a generalized slowness of movement. It eventually affects everyone with PD, and may result in feelings of incoordination.

As the disease progresses, the person may suddenly "freeze up" or take much quicker and shorter steps while walking (called festination).

Rigidity — Rigidity causes stiffened movement of the arms, legs, or body. It usually begins on the same side of the body as other early symptoms, such as tremor and bradykinesia. As the disease progresses, both sides of the body are affected.

Poor balance (postural instability) — In people with PD, the reflexes fail, causing a tendency to fall or to feel off balance.