What is Parkinson’s disease? Causes, symptoms, treatment, and complications

Written by Nicolas Perez Diaz, May 22, 2023.

Parkinson’s Disease or PD is a chronic neurological disorder that affects movement. It is caused by the loss of nerve cells in a part of the brain called the substantial nigra. These nerve cells produce a chemical called dopamine. Parkinson’s is a progressive disorder, which means that the symptoms get worse over time.

Causes of Parkinson’s disease

The exact cause of Parkinson’s is unknown, although a combination of genetic and environmental variables is likely to be the cause.

Genetic factors

Around 10% of sufferers have a family history of the condition. This shows that there might be genes that increase the risk.

Environmental factors

Some environmental factors that are believed to be linked to PD include:

  • Excessive alcohol consumption.
  • Exposure to certain viruses.
  • Exposure to metals.
  • Exposure to pesticides and herbicides.
  • Head injuries.
  • Smoking.
  • Solvents and PCBs (Polychlorinated Biphenyls).

It is important to remember that these are just risk factors and that not everyone who has them will develop Parkinson’s disease.

Signs and symptoms

Numerous signs and symptoms of PD can have a major impact on a person’s day to day activities.  Here are the ones to look out for:

  • Tremor

A trembling or shaking sensation that typically begins in one hand or arm before spreading to other areas of the body. When the person is at rest, the tremor is typically worse and may go away when they are moving.

  • Slowness of movement (bradykinesia)

Walking, talking, and eating are just a few of the motions that it can influence. Patients may have trouble starting their movements, and may move slowly and deliberately.

  • Stiffness (rigidity)

Stiffness is most common in the arms, legs, and trunk. Some people may find it difficult to move their limbs properly.

  • Balance problems

This is a common symptom, especially as the condition progresses. Patients may have trouble standing and walking unaided. As their sense of balance deteriorates, so does their risk of falling and hurting themselves.

Other symptoms may include:

  • Cognitive decline – the patient’s memory, ability to pay attention, thinking ability, and learning skills deteriorate.
  • Constipation.
  • Depression.
  • Difficulty swallowing.
  • Fatigue.
  • Pain.
  • Sleep problems.
  • Urinary problems.
  • Voice changes.

Did you know that the terms signs and symptoms are not the same?

Parkinson's Disease - image listing motor and non-motor impairments

Created by MedicalVocab.com using images from Wikimedia Commons.

Treatment for Parkinson’s disease

There is no cure for PD, but there are treatments that can help to manage the symptoms. Treatment normally includes medication, physical therapy, and lifestyle changes.

Parkinson’s disease medications work by raising dopamine levels in the brain. Levodopa, dopamine agonists, and MAO-B inhibitors are among the most widely used medications.

Movement and balance can be improved with the help of physical therapy. Exercise, a balanced diet, and enough sleep are three changes to your lifestyle that can help manage Parkinson’s disease.


Parkinson’s can lead to a many complications, such as:

  • Falls

Patients are more likely to trip and fall, especially as the condition progresses. This is due to balance and coordination issues. Falls can cause fractures and other types of injuries.

  • Fractures

Bone fractures are more common in people with Parkinson’s disease, especially following a fall. Also, as they get older, their bones become more brittle.

  • Depression

Depression is often overlooked and either under-treated or not treated at all. This is a pity, because proper treatment can significantly improve the patient’s quality of life.

  • Dementia

Memory, thinking, and judgment can all be impacted by dementia, which is a decline in cognitive function.

  • Sleep problems

Some patients find it hard to fall asleep while others find it difficult to stay asleep.

  • Urinary problems

These may include incontinence, difficulty urinating, and frequent urination.

  • Constipation

It may be brought on by how PD affects the digestive system. Constipation can lower quality of life and make it harder to manage and control Parkinson’s disease symptoms. 

  • Pain

This is a common symptom, especially muscle and joint pain.

  • Voice changes

The patient’s voice may become softer, hoarse, or monotonous (almost robotic). Communication difficulties and social isolation can result from voice changes.

  • Difficulty swallowing

Swallowing difficulties can lead to malnutrition. There is also a greater risk of choking.


It is not possible to prevent Parkinson’s disease completely. However, these tips may help reduce your risk:

  • Follow a healthy and well balanced diet.
  • Get enough sleep (good quality sleep).
  • Exercise regularly.
  • Avoid smoking and excessive alcohol consumption.

The University of Maryland Medical System says the following about exercise:

“According to studies, physical activity is not only a good way to treat patients with Parkinson’s disease, it appears to help prevent or delay the onset. Getting the body moving helps build strength, balance, endurance, and coordination. It is even better when the heart is involved, like with aerobic exercise.”