Parkinson disease (also called PD or Parkinson) is the most common form of Parkinsonism, a group of motor system disorders. It is a disease that slowly gets worse over time. While a PD diagnosis is a life-changing event, it has been found that most people and their families have a good quality of life after the initial adjustment period.

PD is caused by the loss of brain cells that make dopamine. Dopamine is a substance that helps with smooth and coordinated muscle movement. Parkinson often causes these symptoms:

• Tremor or trembling of the arms, jaw, legs, and face
• Stiffness or rigidity of the limbs and trunk
• Slowness of movement (bradykinesia)
• Problems with balance and coordination

The cause of Parkinson is unknown. Experts believe the symptoms are linked to a chemical imbalance in the brain caused by brain cell death. Parkinson is chronic. Symptoms grow worse over time.

This disease may appear in younger people (even teenagers). But it often affects people in late middle age. It is not contagious.

Experts think that, in most people, the cause of Parkinson is a mix of genes and the environment. Studies have shown that rural living, exposure to well water, and exposure to agricultural pesticides and herbicides are linked to Parkinson. But these factors don't guarantee you will get the disease. Nor does their absence prevent it.

In the other forms of Parkinsonism, either the cause is known or suspected. Or the disorder occurs as a secondary effect of some other neurological problem. These forms are sometimes called Parkinson syndrome, atypical Parkinson, or, simply, Parkinsonism. They may be caused by:

• Tumors in the brain.
• Repeated head trauma, such as from boxing.
• Long-time use of certain medicines, such as phenothiazines, butyrophenones, or reserpine for mental health problems, and metoclopramide for stomach upset.
• Toxins, such as manganese and carbon monoxide poisoning.
• Postencephalitic Parkinsonism, a viral disease that causes "sleeping sickness."
• Striatonigral degeneration, a disease that affects the part of the brain called the substantia nigra.

Parkinsonism may also occur with other nervous system problems. These include:

• Shy-Drager syndrome.
• Progressive supranuclear palsy.
• Wilson disease.
• Huntington disease.
• Hallervorden-Spatz syndrome (or pantothenate kinase-associated neurodegeneration).
• Alzheimer disease.
• Creutzfeldt-Jakob disease.
• Olivopontocerebellar atrophy.
• Post-traumatic encephalopathy.
• Dementia with Lewy bodies.

The biggest risk factor for Parkinson is advancing age. The average age for Parkinson symptoms to start is 70 years. Men are affected more than women. But the reason for this is unclear.

Family history is another key risk factor. A person with an affected parent or sibling has a higher chance of getting Parkinson. This higher risk is most likely because of a mix of environmental and genetic factors. Having one or more close relatives with Parkinson raises the risk of the disease, as does exposure to environmental toxins.

These are the most common symptoms of Parkinson:

• Rigid muscles. Stiffness when the arm, leg, or neck is moved back and forth.
• Resting tremor. Tremor (involuntary movement from contracting muscles) that is most obvious at rest.
• Bradykinesia. Slowness in starting movement.
• Postural instability. Poor posture and balance that may cause falls or gait problems.

Symptoms of Parkinson vary from person to person. The symptoms may appear slowly and in no certain order. Early symptoms may be subtle. They may slowly get worse over many years before reaching a point where they disrupt normal daily activities.

Other symptoms are divided into motor (movement-related) and nonmotor symptoms.

Motor symptoms:

• Tremor
• Slow movement (bradykinesia)
• Rigidity and freezing in place
• Stooped posture
• Shuffling gait
• Decreased arm swing when walking
• Trouble getting up from a chair
• Small, cramped handwriting (micrographia)
• Lack of facial expression
• Slowed activities of daily living (for example, eating, dressing, and bathing)
• Trouble turning in bed
• Staying in a certain position for a long period of time

Nonmotor symptoms:

• Diminished sense of smell
• Low voice volume (hypophonia)
• Trouble speaking (dysarthria)
• Painful foot cramps
• Sleep problems
• Depression
• Emotional changes (fearful and insecure)
• Skin problems
• Constipation
• Drooling
• Increased sweating
• Urinary frequency or urgency
• Male erectile dysfunction

As the disease gets worse, walking may become affected. It may cause the person to stop in midstride or "freeze" in place, and maybe even fall over. People also may start walking with a series of quick, small steps as if hurrying forward to keep balance. This is known as festination.

The symptoms of Parkinson may look like other health problems. Always see your doctor for a diagnosis.

Diagnosing Parkinson in the early stages can be hard. At first, signs and symptoms may look like other health problems or the effects of normal aging. For this reason, your doctor may want to watch your symptoms for some time until they are consistently there.

Right now, there are no blood or lab tests to diagnose Parkinson. Diagnosis of Parkinson is based mainly on a health history and nervous system exam. Brain scans or lab tests may be done to help rule out other diseases or conditions. But brain scans generally will turn out to be normal with Parkinson.

You may need:

• Neurological exam. This includes testing different functions of the nervous system.
• Trial test of medicines. When symptoms are severe, a trial test of medicines (mainly levodopa or L-dopa) may be used. If symptoms are eased from the use of levodopa, this suggests Parkinson.
• 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.

So far, there is no cure for Parkinson. But your doctor can plan treatment based on the severity of the symptoms and the progression of the disease. PD does not affect people the same way. You may need:

• Medicine.
• Surgery.
• Complementary and supportive therapies, such as diet, exercise, counseling, stress management, physical therapy, occupational therapy, and speech therapy.

Once the diagnosis has been made, the next decision is whether medicine is a choice. This depends on:

• How much the disease has affected your physical activities and thinking.
• Your ability to tolerate antiparkinsonian medicine.
• The doctor's advice and your preferences.

No two people react the same way to a given medicine. It takes time and patience to find the right medicine and dose to ease symptoms.

In some cases, your doctor may advise surgery. Surgery may help with symptoms. But it does not cure the disease or stop it from getting worse.

It may help the tremor or rigidity that comes with the disease. In some people, surgery may decrease the amount of medicine needed to control the symptoms of Parkinson.

There are two types of surgeries for Parkinson disease:

• Lesion surgery (scarring of tissue). In this procedure, small lesions or scars are made in the deep parts of the brain that help control movement. The surgery may be done while you are awake to help find the exact placement of the lesion. The lesion is placed to help control or stop the area of the brain causing the tremor.
• Deep brain stimulation. With this type of surgery, a small electrode is placed in the deep parts of the brain that help control movement. The electrode is attached to a small battery in the chest wall. It is connected by wires that are placed under the skin. The stimulator is then turned on. It interrupts the flow of information in the brain causing Parkinson and can help to decrease symptoms.

Even though Parkinson disease is a chronic, incurable disease, treatment can help ease symptoms and enhance your quality of life. You can also do a lot to stay independent, such as:

• Eating a healthy diet.
• Staying mobile with the use of assistive devices, if needed.
• Exercising regularly.
• Doing physical therapy, occupational therapy, and speech therapy, if needed.

Also talk with your doctor about depression, anxiety, or other mental health issues that may come up.

Community agencies can help you and your family adjust to the diagnosis of Parkinson disease. The Parkinson's Foundation provides a variety of educational resources for patients and family members. It also has a helpline staffed with Parkinson specialists who can offer support to people with PD, caregivers, and health care providers. The helpline provides information about emotional support, current PD-related medical information, and local resources. The helpline is available at 800-4PD-INFO (800-473-4636) or helpline@parkinson.org.

• Parkinson is a motor system disorder. It slowly gets worse over time, but treatment, a healthy lifestyle, and community support can enhance the person's overall quality of life.
• The most common symptoms are muscle rigidity, resting tremor, slowness in starting movement, and postural instability.
• There is no known cure for Parkinson. But medicines and surgery can help control symptoms.
• Healthy diet, regular exercise, physical therapy, occupational therapy, and speech therapy can promote independence.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours and on weekends and holidays.