Parkinson’s Disease

Parkinson's disease is a progressive neurodegenerative disorder that develops when brain cells that produce dopamine die. 

Dopamine is a vital chemical messenger (neurotransmitter) that helps regulate movement. When dopamine is depleted, classic Parkinson's symptoms like slowness of movement, shaking, stiffness, and walking difficulties can occur.

Doctors used to consider Parkinson's disease solely a motor (movement) disorder, but now they know it also causes non-motor-related symptoms like sleep problems, anxiety, loss of smell, and constipation, and that these symptoms may actually predate the motor symptoms by many years or even decades.

Frequently Asked Questions

  • What causes Parkinson's Disease?

    Experts haven’t pinned down the exact cause, but it’s believed that Parkinson’s is caused by certain genes and environmental factors, like exposure to toxins. This leads to brain changes,  which may play causal roles. They are:

    • Death of brain cells that produce dopamine
    • Neurodegeneration
    • Lewy body accumulation
  • Is Parkinson's disease hereditary?

    It’s believed to be, at least in part. Experts don’t know the exact cause(s) yet, but they believe Parkinson’s disease may be caused by a complex interaction between your genes and your environment, which may include toxins like pesticides. Only about 14% of people with the disease have a first-degree relative with Parkinson’s. Risk factors include being over age 60 and being biologically male.

  • What are early warning signs of Parkinson's disease?

    The earliest symptoms of Parkinson’s disease are often non-motor symptoms, including:

    • Constipation
    • Depression and anxiety
    • Reduced sense of smell
    • REM sleep behavior disorder (having vivid dreams, nightmares, acting out in your dreams)

    These symptoms result from neurological changes that will eventually lead to classic Parkinson’s symptoms like tremor, slowness and other movement problems.

  • What are the five stages of Parkinson's disease?

    Parkinson’s progresses through these stages over time:

    1. Mild symptoms, one side of body
    2. Symptoms on both sides of your body
    3. Balance is impaired, movement slows down, disability is apparent
    4. Severe symptoms limit daily activities, movement and walking impairments with falls
    5. Inability to care for yourself, wheelchair is necessary, dementia is possible

    Treatment can prevent progression to later stages.

  • How can I prevent Parkinson's disease?

    Thus far, there’s no known way to prevent Parkinson’s disease. Genetic testing can tell you your risk, which may help with earlier diagnosis and treatment. That, in turn, may slow the progression of the disease. However, it’s not yet possible to prevent the disease from developing.

  • Is there a cure for Parkinson's disease?

    Parkinson’s disease currently has no known cure. However, a number of treatments can ease the symptoms and researchers are always learning more about how to possibly slow down the progression of the disease.

Key Terms

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  1. National Institute on Aging. Parkinson's disease. May 16, 2017.

  2. World Health Organization. What are neurological disorders? May 3, 2016.