Parkinson’s disease

Parkinson’s disease is a progressive neurodegenerative disease that primarily affects the parts of the brain that control movement, resulting in tremors, stiffness, and slowness. Some people living with Parkinson's may also develop dementia in the later stages of the disease.

Midlife woman rests hand on shoulder of midlife man


Parkinson’s disease (often shortened to PD) is a progressive neurodegenerative disease that primarily affects the parts of the brain that control movement. This results in tremors, stiffness, and slowness, while difficulty walking and loss of balance typically emerge as the disease progresses.

Some people may also develop dementia as their PD progresses into the later stages of the disease, often resulting in significant memory loss and difficulty concentrating, thinking, completing routine activities, and navigating the environment. Behavioural problems are also common including depression, hallucinations and delusions.

Idiopathic Parkinson’s disease is another name used for PD.


The age of symptom onset and the progression of PD can vary among people; however, as PD is a progressive degenerative disease, symptoms will gradually worsen with time.

Symptoms of PD are most commonly seen in people over the age of 50 but may begin under the age of 40.

Difficulties with movement

Early symptoms of this disease are often related to difficulties with a person’s movement. These difficulties with movement may be experienced in one or both sides of the body. People with PD may experience movement difficulties, including:

  • Rigidity
  • Tremors
  • Bradykinesia (slowed movements)
  • Loss of balance, or
  • Falls.

People with PD may also complain that they feel “stuck in place” when they try to start walking.

Changes in mood and personality

In addition to movement symptoms, a person with PD may experience changes in their personality, such as irritability, depression and anxiety.

Physical symptoms

Sleep disorders, changes in appetite, dry skin, low blood pressure upon standing and excessive sweating are among the physical symptoms of PD.

Dementia-related symptoms

With the progression of PD, some people will experience changes in their cognitive abilities and may develop dementia. People with cognitive symptoms of PD typically experience difficulties with memory, concentration, carrying out routine activities, and thinking quickly.

Visual hallucinations and the inability to control emotions are also common features of the dementia associated with PD. These symptoms have a tendency to fluctuate, causing them to seem better or worse at different times.


It can be challenging to diagnose PD as there is no single test to identify it, and there are a number of symptoms that are shared with other medical conditions.

The amount of time that it takes to get a PD diagnosis can vary as it depends on a number of different factors, such as:

  • Age,
  • Medical history, and
  • The symptoms present at the time.

Medical history and exams

To help make a PD diagnosis, your doctor will often conduct a comprehensive assessment that may include physical, neurological and psychiatric exams, together with a review of your complete medical history (including a review of current and past medications that could be causing some of the physical symptoms). This thorough assessment helps your doctor rule out other conditions that could be causing the symptoms.

Diagnosis is generally made and confirmed by a neurologist. Diagnosis is typically based on a common pattern of symptoms including tremor, rigidity, and slowness as well as through a detailed physical examination confirming the typical features of the disease.

People living with PD are at an increased risk for developing dementia. Should you be diagnosed with PD, make regular appointments with your doctor so they can monitor you closely for changes in your cognitive abilities.

Brain imaging

If cognitive changes are identified, a physician may request a magnetic resonance imaging (MRI) test to help detect any structural changes in the brain that could be causing the changes in cognition.

Risk factors

At present, there is no known cause of the majority of cases of PD. However, rare genetic abnormalities can sometimes be inherited in families that cause the disease.

Some risk factors have been identified as playing a role in the development of PD, including:

  • Age – the risk of PD increases with age,
  • Gender and sex – men are at an increased risk of PD, and
  • Genetics – having a close relative with PD increases the risk of developing the disease.

Similar to other neurodegenerative disorders, like dementia with Lewy bodies, PD is characterized by an abnormal clumping of a natural protein – called alpha-synuclein – in brain cells.

These abnormal deposits are called “Lewy bodies,” after the scientist who first described them. It is still unknown what causes the formation of Lewy bodies, and why they result in the deterioration of brain cells but researchers believe that these deposits could be linked to the cause of PD.


Currently there is no known cure for PD, although people can live with the disease for many years.


Medications are often used to manage the symptoms of PD. Medications such as Levodopa can lessen people’s challenges with movement.

Medications used in Alzheimer’s disease—such as cholinesterase inhibitors—help to increase brain acetylcholine levels and can also be used to improve symptoms of dementia associated with PD.

Surgical approaches

In some cases, surgery may be recommended for severe motor fluctuations observed in PD depending on the symptoms present.

Therapeutic approaches

Therapeutic approaches also support people living with PD to manage symptoms of their disease:

  • Occupational and physical therapies that are focused on balance and stretching exercises may help to maintain physical functioning throughout the progression of the disease.
  • Speech therapy has also been found to help with the challenges of verbal communication – such as slurred speech – that can be associated with PD.

More information and resources

Parkinson Canada. Parkinson Canada is the country's leading nonprofit organization looking to make a profound difference in the well-being of Canadians living with Parkinson’s disease.