Parkinson’s is a progressive neurological disorder and is considered to be one of the most common neurological conditions.

Every case of Parkinson’s is different and not everyone will experience the same symptoms. For example, not all people develop tremor and for some, rigidity is the major symptom. With modern medication, symptoms can be well controlled.

Our movements are controlled by nerve cells (neurons) in the brain which pass messages to one another, and to the rest of the body, using chemicals called neurotransmitters. An area of the brain called the substantia nigra produces one of the neurotransmitters that controls movement: dopamine. In people with Parkinson’s, 70-80% of dopamine-producing cells gradually deteriorate and are lost – this is called neurodegeneration. Cell death occurs naturally with ageing, but in Parkinson’s the process is much faster.

The loss of dopamine-producing neurons results in low levels of dopamine in the part of the brain that controls movement and balance. When nerve cells do not pass on brain messages properly due to a lack of dopamine, movement is no longer controlled smoothly and the symptoms of Parkinson’s appear. The most common symptoms are tremor, stiffness (rigidity) and slowness of movement.

While dopamine is the main neurotransmitter involved, other neurotransmitters are also affected. This may explain why simply replacing dopamine does not necessarily cause improvement. It may also help to explain why so many people with Parkinson’s also experience non-motor symptoms.

Difficulties that are not related to movement can also occur, such as pain, sleep disturbance and depression. These are known as non-motor symptoms.

If over a period of time you notice that you have some of these symptoms, then your doctor may consider that you have Parkinson’s and will refer you to a specialist for their opinion.

See also About Parkinson's.

The causes of Parkinson's are as yet unknown. Some poisons, mould toxins and synthetic medications, for example, can give rise to the condition. Additionally, there are some genes that can be a trigger if they become damaged. Extensive brain damage can also cause Parkinson's symptoms.

Researchers have not yet been able to find a way to cure Parkinson's or slow its progression, although this is an area of great research. However, with medication symptoms can be effectively controlled to improve your quality of life.

See also Causes.

Parkinson’s is a life-altering, not a life-threatening illness, so you will die with it, not from it. How you die will be dependent on many other factors related to your health and will not be related to Parkinson’s alone.

Due to the complexity of the condition, there is no simple or accessible diagnostic test for Parkinson’s, such as an X-ray or blood test. A clinical diagnosis is always required, which relies on an expert’s clinical assessment.

Parkinson’s is difficult to diagnose because there is no specific test for the condition. Symptoms vary from person to person and a number of other illnesses have similar symptoms, which means misdiagnoses can occur, especially in the early stages when signs and symptoms are subtle. Therefore, the use of established diagnostic tools that detect the loss of dopamine in the brain may be useful and can help to reduce misdiagnosis. DaTSCAN is one such tool that has been shown to differentiate between Essential Tremor and Parkinson’s in the majority of cases. It can identify a loss of dopamine – a chemical known to be depleted in the brain of someone with Parkinson’s - from those who have no loss.

Magnetic resonance imaging (MRI) scans are rarely used for diagnosing Parkinson’s since an MRI of a parkinsonian brain generally looks normal. But MRI can help to differentiate between Parkinson’s and other types of parkinsonism, for example Multiple System Atrophy and Progressive Supranuclear Palsy.

It is therefore essential that specialist advice is made available to people as soon as the early signs and symptoms of Parkinson’s are detected so that treatment options can be explored. As each person is different, it may take several visits to your doctor or specialist at regular intervals to carefully monitor any change or emergence of new symptoms before a diagnosis can be confirmed.

See also Diagnosis.

Sometimes it may take several examinations over a period of time before the diagnosis can be made confidently.

Waiting for a diagnosis can be an anxious time, so if you do have any worries during this period talk to your doctor; he or she will be able to give you further advice and try to reassure you as much as they can.

See also Diagnosis.

Parkinson's Europe has a wealth of information in the About Parkinson's and Living Well sections. There is also a Research section with links to Parkinson's-related research papers published in key neurological journals.

There are many other useful websites and the Internet is an invaluable tool in finding information on Parkinson’s. Do remember though, that just because something has been ‘published’ on the Internet, this does not necessarily mean it is trustworthy or reputable. If you are unsure about the information you have found, print it off and discuss with your doctor or another healthcare professional involved in your care at your next visit.

For tips on using the Internet to find Parkinson's information, see Using computers and the Internet.

Research shows that in most cases Parkinson’s is not hereditary. There have been a few cases where a family reportedly had a hereditary form of the disease, but research shows, that even in identical twin studies, something else triggers this condition.

There are likely to be several genes that predispose an individual to developing Parkinson's as well as environmental factors.

At present there is no genetic test available to determine if a person will develop the condition.

See also Genetic testing.