HEALTH TOPICS 
Parkinson's Disease
What Is It?
Parkinson's disease (PD) is a disease of the central nervous system. It causes problems with body motions, including:
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Tremor (shakiness)
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Rigidity (muscle stiffness)
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Slowed body movements
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Unstable posture
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Difficulty walking
PD develops when certain nerve cells (neurons) in the brain die. These are neurons that produce a chemical called dopamine. Dopamine helps relay messages between areas of the brain that control body movement.
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