Parkinson’s disease

Parkinson’s disease (also called PD or Parkinson disease) is a progressive nervous system disorder that affects movement. Parkinson’s symptoms develop gradually and get worse over time.

There is no cure for Parkinson’s disease, but there are a variety of treatments that can help ease symptoms. Many people with Parkinson’s disease are able to live fulfilling lives after their diagnosis.

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What causes Parkinson's disease?

Different regions of the brain control different functions. The substantia nigra is the region involved in planning and coordinating movement and learning. The nerve cells (neurons) of the substantia nigra produce and respond to a specific chemical signal (a neurotransmitter) known as dopamine.

Parkinson’s disease occurs when the cells in the substantia nigra begin to break down and no longer produce dopamine. As a result, movement becomes delayed or uncoordinated, and other Parkinson’s symptoms begin to develop. The breakdown of cells takes time, meaning that the disease gets worse as time goes on.

Experts remain uncertain about what exactly triggers the neurons in the substantia nigra to break down. Some factors that appear to play a role in Parkinson’s disease are:

  • Genes. Certain genetic mutations appear to be related to Parkinson’s disease. For this reason, a person with a close relative who has Parkinson’s disease is at a slightly higher risk of developing it themselves. However, evidence suggests that there are many genes involved in Parkinson’s, and each mutation only increases risk by a small degree.
  • Environmental exposures. The environment interacts with each person’s genetic sequence in unique and complex ways, so there is no one environmental exposure that causes Parkinson’s. Some evidence suggests that exposure to pesticides and herbicides, metals, and some industrial solvents increases the risk of Parkinson’s disease.
  • Lewy bodies. Lewy bodies are abnormal protein deposits found in high concentrations within the brain cells of people with Parkinson’s disease. Experts aren’t sure what role these proteins play in the development of the disease, but research is ongoing.

Symptoms of Parkinson's disease

Parkinson’s disease affects over 1 million Americans, but each patient’s experience of the disease is different.

While Parkinson’s is a chronic condition, symptoms may fluctuate on and off over the course of days and weeks. This is especially the case in the early stages of the disease.

Parkinson’s disease is classified as a movement disorder because it primarily affects patients’ ability to coordinate movement. However, there can be both motor and non-motor symptoms.

What are early warning signs of Parkinson’s disease?

Early symptoms can be mild and hard to distinguish from normal aging. Some common early symptoms:

  • Less expression. An early sign of Parkinson’s disease is the loss of facial expression, sometimes referred to as “facial masking.”
  • Micrographia. Our handwriting changes as we age. However, if your handwriting has gotten significantly smaller or more crowded (known as micrographia), this may be an early sign.
  • Slight tremor. Tremors are a common symptom of Parkinson’s disease, and may be a warning sign. You may notice only a slight tremor in one hand or even just one finger while at rest.
  • Your arms don’t swing when you walk. Your arms may feel stiff while walking. This and other normal coordination of movements may stop or become more challenging.

Motor symptoms of Parkinson’s

Common motor symptoms of Parkinson’s disease include:

  • Difficulty swallowing or chewing. These symptoms are more common in late stage Parkinson’s disease. The muscles involved in swallowing and chewing may be affected, making it harder to eat. Saliva may accumulate in the mouth and lead to drooling.
  • Loss of balance and poor posture. Parkinson’s patients may become more hunched or have poor posture. This can affect your gait and balance, leading to falls.
  • Rigid muscles. Stiffness when the arm, leg or neck is moved back and forth.
  • Slow movements (bradykinesia). Like tremors, bradykinesia also tends to get worse with time. This can make every day tasks like dressing more time consuming and challenging.
  • Soft or slurred speech. Parkinson’s can slow down and slur your speech. You may speak with more hesitations, or your voice may be more monotone.
  • Tremors. Tremors are involuntary movements that usually start in the limbs. For instance, your hands may shake while at rest, or you may rub your fingers together (pill rolling). Tremors often get worse as Parkinson’s progresses.

Non-motor symptoms of Parkinson’s disease

In addition to movement symptoms, Parkinson’s can have other, non-movement symptoms, including:

  • Constipation. Straining to have a bowel movement is a common symptom of Parkinson’s.
  • Dementia symptoms. Dopamine is involved not only in movement, but in learning. The “dopamine deficit” characteristic of PD can also contribute to cognitive impairment. This is sometimes referred to as Parkinson’s disease dementia, and it includes symptoms like:
    • Memory loss
    • Confusion
    • Difficulty planning or thinking
    • Emotional changes, mood swings and depression
  • Frequent urination or loss of bladder control
  • Loss of smell and taste
  • Pain
  • Sexual dysfunction
  • Sleep disorders. Insomnia, or difficulty falling asleep, is common among Parkinson’s patients. Also, some patients have a sleep behavior disorder which involves acting out dreams.

What are the stages of Parkinson's disease?

Doctors typically define 5 stages of Parkinson’s disease:

  • Stage 1. The earliest stage of Parkinson’s. There may be some symptoms, but they are mild and do not interfere with daily tasks. Usually, tremors or motor symptoms are relegated to only one side of the body. Medications are often effective at controlling symptoms.
  • Stage 2. Parkinson’s is considered moderate. Symptoms like stiffness and tremors are more noticeable than in stage 1. Tasks may take longer to complete and both sides of the body may be affected. However, the Parkinson’s patient can still live alone, and balance remains unaffected.
  • Stage 3. This stage involves more pronounced symptoms that significantly impact daily life. Balance problems become more predominant and basic reflexes decrease. Falls are more common in Stage 3 than other stages. However, between medication and therapy, Stage 3 patients can often retain their autonomy.
  • Stage 4. Symptoms are even more advanced than in stage 3. At this stage, living alone is exceedingly challenging and potentially dangerous. Around a third of patients at this stage have hallucinations or delusions.
  • Stage 5. Also known as end stage Parkinson’s disease, stage 5 is the most advanced stage of Parkinson’s. Muscle stiffness and tremors are severe and can make it impossible to move around. People usually require a wheelchair, and constant surveillance is necessary to prevent falls. Dementia, hallucinations and delusions are common.

Diagnosing Parkinson's disease

Diagnosing Parkinson’s in the early stages can be hard. Early symptoms of the disease can be mistaken for aging or other health problems. In addition, there is no single test for diagnosis of Parkinson’s disease. Instead, your doctor will base your diagnosis on your medical history and symptoms.

Your doctor may also order the following tests to rule out other conditions and support your diagnosis:

  • Neurological tests. Your doctor may test your reflexes and cognitive capacity to better understand your symptoms.
  • Imaging exams. These tests allow your doctor to see your brain. This can help them rule out other conditions, like a brain tumor, that may be causing symptoms. The different types of tests are:
    • CT scan. This imaging test uses X-rays and a computer to make images of the body, including the bones, muscles, fat and organs. CT scans are more detailed than general X-rays.
    • MRI. This test uses large magnets, radio waves and a computer to make detailed images of organs and structures within the body.
  • Medication trials. Your doctor may prescribe a medication, known as carbidopa -levodopa, commonly used to treat Parkinson’s symptoms. If your symptoms improve with this medication, this may be evidence of Parkinson’s disease.

Parkinson's disease: treatment and management

At this time no cure exists for Parkinson’s. However, certain treatments can help provide symptom relief:


Medications can help increase the availability of dopamine or mimic its effects in your brain. This can help with symptoms like tremors, difficulty walking and coordination. Common medications include:

  • Carbidopa-levodopa. This medication actually converts to dopamine when it reaches the brain. It is commonly used both to diagnose and treat Parkinson’s disease. However, as the disease progresses, the benefit of carbidopa-levodopa can decrease. The benefits may wax and wane, a phenomenon known as “wearing off.” Carbidopa-levodopa is commonly taken in pill form, but new delivery methods, like inhalation and infusion, are increasingly available. These can help people with later stage Parkinson’s who experience more “wearing off” of the medication. Other side effects include nausea and lightheadedness.
  • Dopamine agonists. This type of medication mimics the effects of dopamine in the brain. They are often less effective than carbidopa-levodopa, but they have a longer lasting effect. They can also be combined with carbidopa-levodopa to help smooth out the waxing-waning effect. Side effects are similar to that of carbidopa-levodopa, and may also cause sleepiness, hallucinations and impulsive behavior (like gambling and binge eating).
  • MAO B inhibitors. These drugs increase the availability of dopamine in the brain by stopping it from being broken down. It may be combined with levodopa to address “wearing off.”

Deep Brain Stimulation

Deep Brain Stimulation (DBS) is a surgical procedure that may be recommended for people who do not respond well to medication, or for people with significant dyskinesia (involuntary tremors or movements).

The procedure. Your surgeon places thin wire electrodes into the regions of the brain that control movement. These electrodes are connected to a small, battery powered device called a neurostimulator, which is placed near your collarbone. The neurostimulator sends a small amount of electricity to the electrodes in the brain, which seems to regulate the abnormal electrical activity that happens within a brain on Parkinson’s.

The electricity can be adjusted as your needs change over time. Several rounds of “trial and error” may be needed to find the exact setting and combination of medications to optimize your quality of life.

Watch this video to learn more >>


As a motor disease, Parkinson’s disease can make performing everyday tasks challenging.

Our care team includes movement disorder specialists who offer a variety of therapies to help you retain your autonomy and find new ways to go about your life. We offer:

  • Physical therapy, for help with mobility, strength, pain management, learning how to use equipment like a cane and teaching family members or caregivers how to better support you
  • Occupational therapy, for help with self-care tasks and home chores, cognitive and visual rehabilitation, physical performance and fatigue management
  • Speech therapy, for help relearning how to swallow, speak and communicate effectively

Lifestyle Management

In addition to medical treatment, there are plenty of things you can do in your day to day life to improve your symptoms.

  • Exercise. Exercise is a great way to improve your overall well being. It can help improve your flexibility, balance and strength, as well as your mental health. Just be sure to move with care and talk to your care team for support.
  • Eat a varied diet and avoid empty calories.  Your diet plays a big role in your overall health. Make sure you have plenty of protein, healthy fats, vitamins and minerals by eating a balanced and varied diet. Limit foods that can interrupt sleep, like caffeine. Finally, talk to your doctor about your medications, as some work best on an empty stomach.
  • Create a support network. Support is important in everyone’s life, but it’s especially important for a condition like Parkinson’s. There may be support groups in your area.

The outlook for Parkinson’s patients

Being diagnosed with Parkinson’s disease is a life-changing event. After such a diagnosis, you and your loved ones may be shocked and unsure about what the future holds.

While every patient’s experience is different, it’s important to realize that many patients with Parkinson’s can live for decades after their diagnosis.

Finding a care team that meets your needs is key to attaining and maintaining a fulfilling life.


National Institute of Aging (NIA). Parkinson’s Disease: Causes, Symptoms, and Treatments (

MedlinePlus: National Library of Medicine. Parkinson’s Disease (

Parkinson’s Foundation. Parkinson’s (