What is Parkinson’s Disease?

Parkinson's disease (PD) is a movement disorder that is chronic and progressive, meaning that symptoms continue and worsen over time. Nearly one million people in the US are living with Parkinson's disease. The cause is unknown, and although there is presently no cure, there are treatment options such as medication and surgery to manage its symptoms.

Parkinson's disease occurs when a group of cells in an area of the brain called the substantia nigra begin to malfunction and die. These cells in the substantia nigra produce a chemical called dopamine. Dopamine is a neurotransmitter, or chemical messenger, that sends information to the parts of the brain that control movement and coordination.

When a person has Parkinson's disease, their dopamine-producing cells begin to die and the amount of dopamine produced in the brain decreases. Messages from the brain telling the body how and when to move are therefore delivered more slowly, leaving a person incapable of initiating and controlling movements in a normal way.

Parkinson's disease can cause several different symptoms. The specific group of symptoms that an individual experiences varies from person to person. Some of the most common symptoms of Parkinson's disease are:

• tremor of the hands, arms, legs, jaw and face
• rigidity or stiffness of the limbs and trunk
• bradykinesia or slowness of movement
• postural instability or impaired balance and coordination

To learn more:

• Have you been diagnosed with a Parkinson's Plus Syndrome? Read Understanding Parkinson’s Plus Syndromes and Atypical Parkinsonism – to better understand your diagnosis and how it may differ from a diagnosis of Parkinson’s disease.
• Review the most frequently–asked questions that we receive through our Parkinson’s Information Service (PINS), by browsing the PINS Frequently Asked Questions.
• Review general facts about Parkinson’s disease by reading, Ten Frequently-Asked Questions about Parkinson’s Disease.