Parkinson disease (PD) is a movement disorder. It gets worse over time. PD is characterized by:

  • Slowing down of movements—bradykinesia
  • Tremor at rest
  • Muscle rigidity
  • Loss of reflexes that maintain posture and equilibrium
Part of the Brain Affected by PD—Yellow Section
Substansia Nigra
Copyright © Nucleus Medical Media, Inc.


Dopamine is a chemical in the brain. It helps to control movement and emotion. PD is caused by a loss of brain cells that make dopamine. The low dopamine levels cause PD symptoms.

The brain cells may be lost because of:

  • Genetic defects
  • Environmental factors or exposures
  • Combination of genetics and environment

A small amount of people with PD have an early-onset form. This type is caused by a known gene defect. It is passed down from parents.

Risk Factors

PD is more common in men and in people aged 50 years and older. Other factors that increase your chance of PD include:

  • Family members with PD
  • Nonsmokers
  • Exposure to toxins, such as insecticides, carbon monoxide , or manganese
  • IV drug use


Symptoms will be mild at first. They will worsen over time.

PD may cause:

  • Problems with dexterity
  • Difficulty with activities of daily living
  • Fatigue
  • Stiffness and rigidity of muscles, usually beginning on one side of the body
  • Tremors are present at rest, improve with movement, and are absent during sleep
  • Slowness of purposeful movements
  • Neuropsychiatric symptoms, such as:
  • Difficulty and shuffling when walking
  • Poor balance
  • Tendency to fall
  • Loss of smell
  • Sleep problems
  • Flat, monotonous voice
  • Stuttering
  • Trouble speaking (often speaking with a low volume)
  • Increasingly mask-like face, with little variation in expression
  • Drooling and excessive salivation
  • Shaky, spidery, or small handwriting
  • Seborrhea (a skin problem that causes a red rash and white scales)
  • Trouble chewing and swallowing
  • Urinary symptoms (frequency and urgency)
  • Bowel movement symptoms (straining, constipation)


You will be asked about your symptoms and health history. A physical exam will be done. There are no specific tests to diagnose PD. The doctor will ask many questions. This will help to rule out other causes of your symptoms.

Tests to rule out other conditions may also include:

  • Blood tests
  • Urine tests

Imaging tests may be needed to view the brain and spine. This can be done with:


There are no known treatments to cure PD. There are also no proven treatments to slow or stop its progression. Some medications may help to improve symptoms. Over time, the side effects of the medication may become troublesome. The medications may also lose their effectiveness.


Medicines that may be used to treat PD include:

  • Levodopa-carbidopa
  • Dopamine agonists
  • Monoamine oxidase inhibitors
  • Anticholinergics
  • COMT inhibitors
  • Antivirals

Depression or hallucinations may also occur with PD. They can also be caused by treatment. These conditions may be managed with medicine such as:

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Tricyclic antidepressants
  • Antipsychotics

Other medication may help to manage other health risks such as:

  • Bisphosphonates—that may help reduce the risk of hip fractures
  • Various medicine to help manage constipation, drooling, and lightheadedness when standing


Different brain operations are available. Many more are being researched including:

  • Deep brain stimulation (DBS)—implanting a device to stimulate certain parts of the brain to decrease tremor and rigidity
  • Thalamotomy and pallidotomy—destroying certain areas of the brain to improve tremor when medicine does not work (not as common as deep brain stimulation)
  • Nerve-cell transplants (current research)—to increase amount of dopamine made in the brain

Physical Therapy

Therapy can improve muscle tone, strength, and balance. It includes exercises and stretches. There is also evidence that tai chi, yoga , or dance, may also be helpful.

Psychological Support

Consider joining a support group with other people with PD. It will help to learn how others are learning to live with the challenges of PD.

Cognitive Training

Cognitive training works on areas of the brain that control certain functions. It may help improve the ability to do daily tasks. Activities are meant to promote and increase brain fitness through learning or exercises. It works best in conjunction with other healthy lifestyle habits. This training may lead to improvements in reasoning, problem solving, and working memory.


There are no current guidelines to prevent PD.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 09/2018 -
  • Update Date: 07/13/2018 -