What Is Parkinson’s Disease? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Parkinson’s disease is a movement disorder that happens when nerve cells (neurons) in a certain part of the brain are no longer making the chemical dopamine.

The condition is also sometimes known as paralysis agitans or shaking palsy.

The Parkinson’s Foundation estimates that 60,000 Americans are diagnosed with Parkinson’s every year. But the true number of people who develop the disease may be much higher. (1)

History of Parkinson’s Disease

Symptoms and possible treatments for Parkinson’s were discussed in texts related to Ayurveda, an ancient Indian medical practice that’s been around since as early as 5,000 B.C. (2) A Parkinson’s-like condition was also mentioned in the first Chinese medical text, the Huangdi Neijing, more than 2,500 years ago.

Parkinson’s disease was formally recognized in an 1817 paper, “An Essay on the Shaking Palsy,” by James Parkinson, a London apothecary-surgeon and member of the Royal College of Surgeons. (3)

Parkinson (1755–1824) observed what are now known as the classic symptoms of Parkinson's disease, including tremors, rigidity, and postural instability. He theorized that the disease developed because of a problem in the brain’s medulla region.

Parkinson’s essay received little attention until 1861, when French neurologist Jean-Martin Charcot and his colleagues distinguished the disease from other neurological conditions and termed it “Parkinson's disease.” (3)

What Is Parkinsonism? Is It Different From Parkinson’s?

Parkinson’s disease is the most common cause of parkinsonism, a category of neurological diseases that cause slowed movement. (4)

No quick or easy diagnostic tests exist for Parkinson’s disease, so a patient may receive an initial diagnosis of parkinsonism without a more specific condition being confirmed.

Classic Parkinson’s disease — referred to as idiopathic because it has no known cause — is the most common and most treatable parkinsonism.

About 15 percent of people with parkinsonism have atypical variants, which are also known as Parkinson’s-plus syndromes. (5)

Learn More About Parkinsonism

• Tremors, or shaking movements
• Bradykinesia, or slowed movement that all people with Parkinson’s experience
• Rigidity, or stiffness
• Postural instability, or issues with balance
• Parkinsonian gait — walking while stooped over, or a combination of freezing and quickening of gait

Among the most common nonmotor symptoms are:

• Cognitive issues like dementia
• Psychosis, or thoughts and beliefs that aren’t rooted in reality
• Mood disorders such as depression and anxiety, or feelings of apathy
• Sleep disorders like insomnia

The primary symptoms of Parkinson’s disease — tremors, muscle stiffness, slow movement, and impaired balance — can vary from person to person depending on what subtype of Parkinson’s they have, but they generally get worse over time. According to a research article published in the journal Movement Disorders, the three Parkinson’s subtypes are:

• Akinetic-rigid The predominant symptoms are stiffness, slowed movement, balance issues, and gait difficulties.
• Tremor-dominant The predominant symptoms are tremors.
• Mixed Predominant symptoms are a combination of the above two subtypes.

Parkinson’s symptoms often begin on one side of the body and gradually affect both sides of the body, but they tend to be worse on the side they affected first.

Learn More About Signs and Symptoms of Parkinson’s Disease

Stages of Parkinson’s Disease

Neurologists usually describe the progression of Parkinson’s symptoms in stages, using the system known as the Hoehn and Yahr scale. (6) These stages are:

• Stage 1 Symptoms are seen on one side of the body only.
• Stage 2 Symptoms are seen on both sides of the body. There’s no impairment of balance.
• Stage 3 Balance impairment has begun. In this mild-to-moderate stage of the disease, the person is still physically independent.
• Stage 4 This stage is marked by severe disability, but the person is still able to walk or stand unassisted.
• Stage 5 The person requires a wheelchair or is bedridden unless assisted.

The signs and symptoms of Parkinson’s are divided into two categories: motor and nonmotor. Motor symptoms of Parkinson’s affect one’s movement, whereas nonmotor Parkinson’s symptoms are unrelated to movement.

There aren’t any specific tests to diagnose someone with Parkinson’s disease.

Doctors typically make a diagnosis based on the following:

• Medical history
• A neurological exam
• Blood and lab tests (to rule out other disorders)
• Brain scans (to rule out other disorders)

Sometimes, people who have a known inherited form of Parkinson’s disease can take a gene test to determine their risk for developing the disease. (17,18)

Prognosis of Parkinson’s Disease

As Parkinson’s progresses, symptoms often worsen. Some people who respond well to therapy have minimal disability issues. Others, however, become severely incapacitated.

Although Parkinson’s isn’t considered a fatal disease itself, it can cause life-threatening complications that may shorten your life span.

Today, most people living with Parkinson’s disease have close to a normal life expectancy. (19)

For decades, doctors couldn’t treat Parkinson’s disease effectively and thought it was a terminal illness. In the late 19th century, arsenic, morphine, hemlock, and cannabis were used to treat tremors. (3)

By the 1940s and 1950s, neurosurgeons had begun to perform surgery on the basal ganglia of the brain, which resulted in improvements in Parkinson’s disease symptoms. While this surgery was sometimes effective, it was also risky — about 10 percent of patients died as a result of the operation. (3)

The biggest advance in Parkinson’s treatment came in the 1960s. Researchers identified differences in the brains of people with Parkinson’s associated with low levels of the chemical dopamine, which plays a role in coordinated movement. (3)

There’s no cure for Parkinson’s, but a number of treatments can help manage the disease’s symptoms. (17)

Medication Options

Medications for Parkinson’s disease fall into three general categories:

• Medications that increase the level of the neurotransmitter dopamine in your brain
• Medications that affect other neurotransmitters, to help control motor symptoms
• Medications to help control nonmotor symptoms

Treating Parkinson’s disease with medication can be a balancing act between managing the disease and managing drug side effects.

Learn More About Medications for Parkinson’s Disease

Surgical Options

Deep brain stimulation surgery is an option for people with Parkinson’s disease who no longer respond to medications.

With this method, doctors implant electrodes in specific areas of the brain. The electrodes connect to a generator that’s implanted in the patient’s chest. The generator sends electrical pulses to the brain, which help reduce symptoms. (17,18)

Alternative and Complementary Therapies

Some people with Parkinson’s disease use complementary therapies to manage their symptoms.

These approaches may include:

• Exercise Staying physically active can improve flexibility, strength, and mobility.
• Diet A healthy diet can promote overall health for people with Parkinson’s disease.
• Massage A massage may help lessen muscle tension and make you more relaxed.
• Tai chi This ancient type of Chinese exercise can improve balance, strength, and flexibility.
• Yoga Yoga involves stretching and poses that can help with flexibility and balance.
• Meditation Some people report that meditation can reduce pain and stress.
• Feldenkrais method These movement lessons have been shown to reduce depression and improve quality of life. (26)
• Alexander technique This method focuses on muscle posture and balance. (17,18)
• Boxing Instructors at the nonprofit organization Rock Steady Boxing teach boxing exercises to help improve agility, muscular endurance, and hand-eye coordination among people with Parkinson’s. Find a class in your area.

Learn More About What to Eat if You Have Parkinson’s Disease

Prevention of Parkinson’s Disease

Researchers don’t know of any proven ways to prevent Parkinson’s disease, but avoiding certain risk factors and adopting a healthy lifestyle may reduce your risk.

Some studies have shown a diet high in antioxidants along with regular exercise may play a role in preventing Parkinson’s. Other findings have suggested that compounds like caffeine, niacin, and nicotine may have a protective effect against Parkinson’s disease. (21)

Researchers have studied various formulations of nicotine — including intranasal, transdermal, and chewing gum — to see whether they could help with Parkinson’s symptoms, but so far none has been found effective at slowing the progression of Parkinson’s.

According to the Parkinson’s Foundation, nearly 1 million people in the United States are living with the disease. More than 10 million people worldwide have Parkinson’s. (1)

About 4 percent of people with Parkinson’s are diagnosed before age 50. (1)

Men are 1.5 times more likely to develop the disease than women. (1)

Many conditions can cause symptoms that are similar to those of Parkinson’s disease, including the following:

• Essential tremor
• Normal pressure hydrocephalus
• Dementia with Lewy bodies 
• Multiple system atrophy (MSA)
• Progressive supranuclear palsy (PSP)
• Corticobasal degeneration (CBD) (18,24)

American Parkinson Disease Association (APDA)

This organization funds patient services, educational efforts, and research related to Parkinson’s disease. Check out their resources for veterans with Parkinson’s, early-onset Parkinson’s, and caregivers. Interested in getting involved? Find your local chapter.

Davis Phinney Foundation for Parkinson’s

Geared toward helping people with Parkinson’s disease live well, this foundation educates patients and caregivers about wellness through its Live Well TODAY webinar series and its Every Victory Counts manual.

European Parkinson’s Disease Association (EPDA)

The leading Parkinson’s organization in Europe, this association offers free resources on home-based workouts for people with Parkinson’s, how to create a “Parkinson’s Passport” for use while traveling, and more.

The Michael J. Fox Foundation for Parkinson’s Research

This foundation was founded in 2000 by the actor Michael J. Fox, who received a diagnosis of young-onset Parkinson’s disease in 1991. Take a look at Parkinson’s 360, the foundation’s guide for living with Parkinson’s. Or if you’d like to join a Parkinson’s research study, visit the Fox Trial Finder.

Parkinson’s Foundation

With a mission to empower people with Parkinson’s, this foundation funds research geared toward improving care and treatment for the disease. Sign up for their newsletter to receive news updates and information about Parkinson’s resources. Or if you need help connecting with a health professional, call the foundation’s helpline at 800-4PD-INFO (800-473-4636).

Learn More About Additional Resources and Support for Parkinson’s Disease