How is Parkinson's diagnosed?

Research suggests that Parkinson’s tends to develop gradually. It may be many months, even years, before the symptoms become obvious enough for someone to visit their GP.

This information looks at how Parkinson’s may be diagnosed, and explains some of the tests that may be involved in the process.

Parkinsonism is a term used to describe a condition when someone experiences slowness of movement  and at least one other of these symptoms:

Idiopathic Parkinson’s

The most common form of parkinsonism is idiopathic Parkinson’s, or Parkinson’s.

Idiopathic means the cause is unknown. Parkinson’s can cause many symptoms and these can vary from person to person. 

Common symptoms of Parkinson’s include:

Typical early symptoms which you might notice include:

Everyone’s experience is different and not everyone will experience all of these symptoms.

If you’re worried about symptoms you’ve been experiencing, you should visit your GP. 

Before your appointment, think about your symptoms. For example, do your symptoms get worse at certain times? How do they affect your day-to-day life? You may find it helpful to write these down.

You may also want to think about anything else you think your GP needs to know, such as any medication you’re taking, or questions you’d like to ask. This can help if you’re feeling anxious or worried and to get the most out of your appointment. 

During the appointment your GP will ask you questions about your mental and physical health. Try to be as honest as possible. Give them as much detail as you can about how you’re feeling and what your symptoms are.

If your GP suspects you have Parkinson’s, clinical guidelines recommend they should refer you quickly to a specialist with experience in diagnosing the condition.

It’s not always easy to diagnose Parkinson’s. There’s currently no single or definitive test that can diagnose the condition and there are other conditions that have similar symptoms.

The risk of developing Parkinson’s increases with age. Most people who get Parkinson’s are aged 50 or over, but younger people can get it too. 

Before your appointment with a specialist, you may find it helpful to keep a diary or record of your symptoms to help you explain what’s been happening. Taking a list of questions you want to ask can also be useful so you don’t forget to mention something you want to know about.

It may be helpful to take someone with you for support when you see a specialist. If a healthcare professional says something you don’t understand, don’t be afraid to ask them to explain what they mean.

At your appointment

Your specialist will take a detailed medical history and examine you. 

You may be asked to:

  • write or draw something – to see if your writing is small or gradually fades
  • walk – to see whether your arms naturally swing while you move or your stride length gets shorter or slower
  • speak – to see if your voice is soft or very quiet

Your specialist will also look at and ask you:

  • if your face has a ‘masked’ look or if you have problems with facial expressions. This can be a symptom of Parkinson’s
  • if you experience a tremor, any stiffness (rigidity) or slowness of movement

As well as looking for any of the typical signs of Parkinson’s, the specialist will also look for signs that may mean you don’t have Parkinson’s, for example:

  • Essential tremor
    A tremor is an uncontrollable movement that affects a part of the body, for example,  the hand. Essential tremor is the most common type of tremor and is most obvious when your hands are doing something. Essential tremors often ease when your body is resting. It usually affects both the right and left  sides of the body equally. A Parkinson’s tremor is most obvious when you’re resting and tends to be less noticeable when you’re moving. It usually starts on one side of the body and may progress to the other side as Parkinson’s develops.
  • Dementia with Lewy bodies
    Dementia with Lewy bodies shares some symptoms with Parkinson’s, such as rigidity, thinking more slowly and anxiety or depression. If you’ve noticed changes in your thinking and memory, you should talk to your GP. It's important to act early as there may be treatments that you can benefit from and things that you can do to improve your symptoms.

Read more about thinking and memory changes.


Response to Parkinson’s drugs

After examining you, and depending on how much your symptoms affect you, your specialist may suggest you start taking medication for Parkinson’s. 

If your symptoms improve after taking Parkinson’s medication for a few weeks or months, your specialist may confirm Parkinson’s diagnosis. 

But some people with other forms of parkinsonism will also respond well to these drugs. So your specialist will review your diagnosis regularly depending on how your symptoms develop. 

Read more about types of parkinsonism.

Your specialist may suggest you have a scan to help make a diagnosis. But scans alone can’t definitely diagnose Parkinson’s, so they’re not always used.

MRI or CT scans

An MRI or CT scan looks at the structure of your brain. These scans can’t diagnose Parkinson’s, but they can be helpful in diagnosing other types of parkinsonism.


These are scans that can tell your specialist how different areas of your brain are working. SPECT is a type of imaging test that shows how blood flows to tissues (muscles, for example) and organs.

A dopamine transporter scan, known as a DaTSCAN, is a type of SPECT scan that can tell your specialist if you’ve lost dopamine-producing brain cells. It’s the loss of these cells that causes Parkinson’s to develop.

But losing dopamine-producing brain cells may also be a sign of some other, rarer neurological conditions. So an abnormal DaTSCAN result alone can’t definitely prove you have Parkinson’s.   

A normal DaTSCAN can be helpful in showing that a person’s symptoms, particularly tremor, are not caused by Parkinson’s. But your symptoms may be due to another condition, such as essential tremor. 

Other specialist tests

Your specialist may also request other specialist tests. These include:

  • a metaiodobenzylguanidine (MIBG) scan of your heart
  • a lumbar puncture, which tests the spinal fluid that surrounds your brain
  • electrical recording (EMG) of the urethral or anal sphincter, to check the health of the muscles and nerves that control them. Your anal sphincter is the muscle that controls your back passage, while your urethral sphincter muscle controls the tube that takes urine (pee) out of your body when you pee
  • autonomic function tests (AFTs) to record your pulse and blood pressure

Sometimes a test or a series of tests can help strengthen the case for a specific diagnosis, or rule out a condition. But this is only after your specialist has considered your symptoms and the results from your medical examination. 

The time it takes to get a diagnosis is different for everyone. 

Some people may receive a diagnosis of Parkinson’s quite quickly, but for others it may be a long process. This can 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 or see how you respond to treatment. Keeping a diary or record of your symptoms will give your specialist more information to guide their decision.  

Waiting for a diagnosis can be stressful. You may feel anxious or frustrated that someone can’t tell you what’s wrong. Other people may feel angry that this is happening at all or worried about what a diagnosis might mean for the future. The uncertainty can feel overwhelming.

These feelings are all normal and there is no right or wrong way to deal with them. For some people, talking with friends or family can help. You can also speak to others who are currently being diagnosed, or have already gone through a similar experience, on our online forum.

You may want to look for more information about Parkinson’s while you wait for a diagnosis, to help you feel more informed. You can read more about living with Parkinson’s on our Information and Support pages. All of our information is checked by experts and other people with Parkinson’s, so you know it’s information you can trust.

Being diagnosed with Parkinson’s can be a very emotional experience. Some people feel shocked or confused – others feel angry or anxious. Some people even feel relieved to have an explanation for their symptoms. 

If you’re waiting for a diagnosis or have just been diagnosed and have any questions, you can call our helpline on 0808 800 0303 or email [email protected] 

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

However, 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’s currently no definitive test for Parkinson’s, some experts prefer to use the term ‘parkinsonism’  when diagnosing people. They may only specifically diagnose Parkinson’s if they see your condition following the typical pattern. 

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 which could be linked to Parkinson’s. They are also 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, sniffer dogs and looking for other chemical markers of the condition in the blood or on the skin. 

It’s difficult to say how long it will be before new and better tests for diagnosing Parkinson’s become available, but research in this area is a major focus for Parkinson’s UK. Better ways of diagnosing and monitoring Parkinson’s could also help make research studies more efficient, leading to better treatments in the future.

Find out more about our research.

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"Getting a diagnosis wasn’t easy, but I’m learning more every day and gradually adapting to life with Parkinson’s."

Daxa shares the 3-year journey she had to receive a Parkinson's diagnosis – and how she's gradually learning to adapt to the challenges.

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Last updated

Next update due 2027 

If you'd like to find out more about how we put our information together, including references and the sources of evidence we use, please contact us at [email protected]