Parkinson disease is a movement disorder. It can cause the muscles to tighten and become rigid. This makes it hard to walk and do other daily activities. Many people with Parkinson disease also have tremors. In later stages, some with Parkinson disease may develop cognitive problems, including memory loss and dementia.

Parkinson disease is most common in people who are older than age 50. The average age at which it occurs is 60. But some younger people may also get Parkinson disease. When it affects someone younger than age 50, it's called early-onset Parkinson disease. You may be more likely to get early-onset Parkinson disease if someone in your family has it. The older you are, the greater your risk of developing Parkinson disease. It's also much more common in males than in females.

Parkinson disease is a chronic and progressive disease. It doesn't go away and gets worse over time.

Parkinson disease is caused by decreased dopamine production in the brain. The absence of dopamine makes it hard for the brain to coordinate muscle movements. Low dopamine also leads to mood and cognitive problems later in the course of the disease. Experts don't know what triggers Parkinson disease most of the time. Early-onset Parkinson disease is often inherited. It's the result of certain gene defects.

Parkinson disease symptoms often start out mild. They then gradually get much worse. The first signs are often so subtle that many people don't get medical care for them. These are common symptoms of Parkinson disease:

• Tremors that affect the face and jaw, legs, arms, and hands
• Slow, stiff walking
• Trouble maintaining balance
• Problems with coordination
• A stiff feeling in arms, legs, and torso area
• Changes in handwriting

Eventually, Parkinson disease symptoms get worse and may include:

• Depression
• Gastrointestinal problems (like constipation)
• Problems with urination
• Trouble chewing and swallowing food
• Memory loss
• Hallucinations
• Dementia
• Weight loss

Parkinson disease can be hard to diagnose. No single test can identify it. Parkinson disease can be easily mistaken for another health condition. A doctor will often ask about your medical history and family history to find out if anyone else in your family has Parkinson disease. They'll also do a neurological exam. Sometimes MRI, a CT scan or some other imaging scan of the brain can find other problems or rule out other diseases.

Parkinson disease can't be cured. But there are different therapies that can help control symptoms. Many of the medicines used to treat Parkinson disease help to offset the loss of the chemical dopamine in the brain. Most of these medicines help manage symptoms quite well.

Some people may need surgery to manage symptoms. A procedure called deep brain stimulation (DBS) may be used to treat Parkinson disease. During DBS, wires are surgically implanted into the brain. Electrical impulses go through the wires into the brain, helping to control tremors and twitching movements. DBS isn't a cure. A person must meet specific clinical criteria for it to be considered. DBS isn't used for people with significant dementia.

Surgery may involve destroying small areas of brain tissue causing the symptoms. But these surgeries are rarely done since deep brain stimulation is now available.

Parkinson disease causes physical symptoms at first. Problems with cognitive function, including forgetfulness and trouble with concentration, may start later. Some people with Parkinson disease develop dementia. This is more likely if you are older or have had Parkinson disease for many years. This can cause profound memory loss and make it hard to maintain relationships. This often happens later in the course of the disease.

Parkinson disease dementia can cause problems with:

• Speaking and communicating with others
• Problem solving
• Understanding abstract concepts
• Forgetfulness
• Paying attention

If you have Parkinson disease and dementia, you likely won't be able to live by yourself at some point. Dementia affects your ability to care for yourself, even if you can still physically do daily tasks.

Experts don't understand how or why dementia often occurs with Parkinson disease. But it's clear that dementia and problems with cognitive function are linked to changes in the brain that cause problems with movement. As with Parkinson disease, dementia occurs when nerve cells break down, leading to chemical changes in the brain. Parkinson disease dementia may be treated with medicines also used to treat Alzheimer disease, another type of dementia.

Experts don't yet understand how to prevent Parkinson disease. In some cases, there seems to be a genetic predisposition to develop Parkinson disease. But this isn't always the case. Research is underway to find new ways to treat and prevent the disease.

These measures can help you live well with Parkinson disease:

• An exercise routine can help keep muscles flexible and mobile. Exercise also releases natural brain chemicals that can improve emotional well-being.
• High protein meals can benefit your brain chemistry.
• Physical, occupational, and speech therapy can help your ability to care for yourself and communicate with others.
• Consider meeting with a medical social worker with expertise in Parkinson Disease. This person can help you discuss how the disease might affect your future plans.

Contact your doctor if you or your loved one notices:

• A sudden or major change in symptoms.
• Mood changes.
• Increased symptoms of depression.
• Feelings of suicide.

Let your doctor know if you have questions about daily and long-term management of symptoms as the disease progresses.

• Parkinson disease is a movement disorder that can make your muscles tight and rigid.
• It can make walking and taking care of yourself hard to do.
• It can lead to problems such as depression, hallucinations, and dementia.
• Parkinson disease will get worse, but medicines can help with some symptoms.
• Support from health care providers, family, and friends is important for managing the disease in the long term.

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 don't 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, including after office hours and on weekends and holidays.