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How is Parkinson's diagnosed?

Parkinson’s tends to develop gradually and it may be many months, even years, before the symptoms become obvious enough for you to go to the doctor.

This information looks at what happens next after seeing your GP and how Parkinson's is diagnosed.

Who should I speak to if I think I might have Parkinson’s?

If you are worried about symptoms you have been experiencing, you should visit your GP.

If they suspect you have Parkinson’s, they should refer you to a Parkinson’s specialist doctor before you have any treatment. The National Institute for Health and Care Excellence (NICE) recommends you should see a specialist within 6 weeks.

It's not always easy to diagnose Parkinson's, so it’s important that you see a Parkinson’s specialist to get an accurate diagnosis and to find out the best treatment options.

Find out more about how to prepare for a GP appointment.

How is Parkinson’s diagnosed?

Confirming someone has Parkinson’s can take some time as there are other conditions with similar symptoms. There is also currently no definitive test for diagnosing Parkinson’s.

Investigating symptoms

Parkinson’s should be diagnosed after having a consultation with a specialist. A Parkinson’s specialist will take a detailed neurological history and examine you.

If you have been referred to a specialist, you may find it helpful to keep a diary or record of your symptoms to help you explain what’s been happening to you.

Find out more about keeping a diary and monitoring your symptoms.

There are many different symptoms related to Parkinson’s and these can vary from person to person.

Early symptoms may include:

Your symptoms may be worse when you're stressed or ill.

Looking for signs of Parkinson’s

Your specialist will examine you to look for common signs of Parkinson’s. You may be asked to:

  • write or draw – to see if your writing is small or gradually fades
  • walk – to see whether there is a reduction in the natural swing of your arm or in your stride length and speed
  • speak – to see if your voice is soft or lacks volume

The specialist will also look at your:

  • face – to see if there is a ‘masked’ look or if you have difficulty with facial expressions
  • limbs – to see if you have a tremor, any stiffness (rigidity) or slowness of movement

As well as examining you to look for any of the typical signs of Parkinson’s, the specialist will also look for any other signs that may suggest a different diagnosis.

It may be helpful to take someone with you for support when seeing a specialist. You can also take a list of questions you want to ask as a reminder. If the specialist says something you don’t understand, don’t be afraid to ask them to explain what they mean.

Response to Parkinson’s drugs

After examining you, your specialist may suggest you take medication for Parkinson’s.

If your symptoms improve after taking Parkinson’s medication for a few weeks or months, your specialist may confirm a Parkinson’s diagnosis. However, some people with other forms of parkinsonism will also respond well to these drugs.

Other medical tests or scans that may confirm a diagnosis of Parkinson’s

Your specialist may suggest you have a scan to help make a diagnosis. None of these scans alone can make a definite diagnosis of Parkinson’s.

MRI or CT scans

These are brain-imaging scans and can tell your specialist what the structure of your brain looks like.

Brain scans of people with Parkinson’s usually look normal, but can be helpful in diagnosing other types of parkinsonism. The scan may not look normal in some of the rarer forms.

SPECT or DaTSCAN

These are scans that can tell your specialist how different areas of the brain are working.

SPECT is a type of imaging test that shows how blood flows to tissues and organs.

A certain type of SPECT scan has become widely used for helping specialists confirm the loss of a type of brain cell containing a chemical called dopamine. This type of scan is known as a dopamine transporter scan or DaTSCAN.

It is the loss of these dopamine producing cells that causes the development of Parkinson’s. But similar loss may also occur in some other rarer neurological conditions. So an abnormal DaTSCAN result can't give a definitive diagnosis of Parkinson’s.

A normal DaTSCAN can be helpful in showing that a person’s symptoms are not caused by Parkinson’s, but may be due to another condition. For example a tremor may be caused by essential tremor, not Parkinson's.

Essential tremor is the most common type of tremor. It is most noticeable when your hands are doing something and it usually affects both the right and left sides of the body equally.

Essential tremors often lessen when your body is resting. Unlike an essential tremor, a Parkinson’s tremor is most obvious when the affected body part is resting and tends to be less noticeable with movement.

How long will it take to get a confirmed diagnosis of Parkinson’s?

The time it takes to get a confirmed diagnosis can vary from person to person. Some people may receive a diagnosis of Parkinson’s quite quickly, but for others it may be a long process. This may be due to a number of things, including your medical history, your age and what symptoms you have.

Your specialist may wish to rule out other causes of your symptoms first and see how you respond to treatment. This may also take some time. And, as already mentioned, there is currently no definitive test for Parkinson’s.

How you respond to treatment may help your specialist make a diagnosis.

Is it possible to be misdiagnosed with Parkinson's?

Because the symptoms of Parkinson’s may be similar to other forms of parkinsonism, people can sometimes be misdiagnosed.

It is difficult in the early stages to be certain what type of parkinsonism someone has. This is because your response to medication can be unclear as different forms of Parkinson’s can respond to medication. But as time goes on, depending on what symptoms you have, and your response to Parkinson’s medication, a specialist may be able to offer a more accurate diagnosis.

As there is currently no definitive test for Parkinson’s, some experts prefer to use the term parkinsonism. They may only use Parkinson’s once they have seen your condition following the typical pattern.

Will it be easier to diagnose Parkinson’s more accurately in the future?

Researchers are currently exploring new and different ways to diagnose and monitor Parkinson’s more accurately. These include looking at skin cells and blood samples to spot tiny but significant changes, and developing new and more sensitive imaging techniques, such as ultrasound.

Other research areas include whether some of the very early symptoms of Parkinson’s, such as problems with sense of smell, can be detected using tests such as scratch and sniff tests and looking for other chemical markers of the condition in the blood.

Find out more about our research.

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Diagnosing Parkinson's (PDF, 250KB)

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