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Parkinson’s disease is a movement disorder caused by the loss of dopamine-producing cells in a part of your brain called the substantia nigra.

Parkinson’s is the second most common neurodegenerative disorder behind Alzheimer’s disease. It affects nearly a million people in the United States.

No single test can definitively confirm that you have Parkinson’s disease. Doctors make a Parkinson’s diagnosis clinically, meaning they use their judgment to make the diagnosis after:

  • reviewing your medical history
  • examining your symptoms
  • ruling out conditions that cause similar symptoms

Read on to learn more about the symptoms that can be early signs of Parkinson’s disease and how a Parkinson’s diagnosis is made.

Parkinson’s disease is a progressive condition, and symptoms tend to get worse over time. The rate of progression varies between people.

At first, symptoms tend to be mild enough that they likely won’t interfere with your daily life. But people who regularly spend time with you may notice changes in your gait, posture, or facial expressions.

Parkinson’s symptoms usually start on one side of your body before progressing to both sides. The four primary symptoms of Parkinson’s include:

Symptoms vary between individuals. For example, about 25 percent of people with Parkinson’s don’t experience a tremor.

Even if you don’t exhibit all the symptoms, you need to have slowness of movement for your doctor to make the diagnosis. Slowness of movement might manifest in numerous ways, such as:

  • reduced blinking rate
  • lack of facial expression
  • trouble initiating movements like standing from a seated position

Along with these four primary signs, other early symptoms of Parkinson’s can include:

Parkinson’s also commonly causes non-motor symptoms in the early stages. There’s substantial evidence that these non-motor symptoms can appear several years before diagnosis, including:

What’s next?

If you begin to notice these symptoms gradually progressing, developing a treatment plan early is crucial.

If you notice any changes in your movement that you believe could be signs of Parkinson’s, visit a primary care physician. If they suspect that you may have Parkinson’s, they’ll refer you to a neurologist who specializes in movement disorders.

Doctors diagnose Parkinson’s clinically based on your symptoms and medical history.

No individual test can be used to diagnose Parkinson’s. Many other neurogenerative conditions can lead to similar symptoms, so your doctor may use a blood test, brain scans, or other tests to rule out other conditions.

Medical history and physical exam

The process of diagnosing Parkinson’s usually begins with the neurologist evaluating your medical history and performing a physical exam. For a formal diagnosis to be made, you need to have a general slowness of movement with either a resting tremor or rigidity.

During the physical exam, your doctor will have you perform a series of tests to monitor your movement. An example of a test they might use is a finger tap, where they measure how many times you can tap your finger in 10 to 15 seconds.

They will also look for signs that you may have another condition. A group of movement disorders collectively called parkinsonisms can produce symptoms that are indistinguishable from those of Parkinson’s but are not the same. Usually, additional tests are needed to rule out these conditions as well.

Blood tests and spinal fluid tests

A blood test or spinal fluid test can’t be used to diagnose Parkinson’s. But they can be used to search for certain proteins that indicate you may have another neurodegenerative condition with similar symptoms.

The presence of elevated levels of a nerve protein called neurofilament light chain protein may indicate that you have another movement disorder, such as:

  • multiple system atrophy
  • progressive supranuclear palsy
  • corticobasal degeneration

Genetic testing

Most people who have Parkinson’s don’t have a family history of the disease. But there does seem to be a genetic link in about 10 percent of cases.

Researchers have found that mutations in some genes seem to be linked to the development of Parkinson’s, such as:

  • PINK1
  • PARK7
  • SNCA
  • LRRK2

If you have a family history of Parkinson’s, genetic testing may provide supportive evidence for a Parkinson’s diagnosis.


Your doctor may refer you for imaging tests to help rule out conditions similar to Parkinson’s.

The brain of somebody with Parkinson’s looks the same as the brain of a person without the disease when examined with most imaging tests, such as magnetic resonance imaging (MRI). But an MRI can be used to rule out conditions such as normal pressure hydrocephalus or a subcortical stroke.

An imaging technique called a DaTscan can be used to identify the loss of dopamine in your brain. This may help medical professionals differentiate between essential tremor and Parkinson’s.

Response to medication

Although it’s not used as a primary diagnostic method, if the medication levodopa helps manage your symptoms, it provides supportive evidence that you have Parkinson’s.

Usually, other movement disorders that cause similar symptoms don’t respond to Levodopa or don’t respond for long.

By the time Parkinson’s causes noticeable motor symptoms, usually about 50 percent of the cells that produce dopamine in your substantia nigra have already died off. Non-motor symptoms, such as constipation, loss of smell, or restless sleep, often appear before motor symptoms.

There’s still debate among medical professionals on how long non-motor symptoms may appear before an individual has noticeable changes in their movement. It’s thought that they could appear years to decades beforehand.

But a formal Parkinson’s diagnosis requires the symptom slowness of movement. In the time before this symptom appears, your doctor can’t make a Parkinson’s diagnosis, but they may alert you that you’re at a high risk of developing Parkinson’s in the future if these or other symptoms appear at any point.

If your doctor doesn’t diagnose Parkinson’s, they can help you find out what the best next step is depending on what condition they suspect. In some cases, treatment may be as simple as changing the dosage of a medication that may be leading to Parkinson’s-like symptoms.

Receiving a Parkinson’s diagnosis can be overwhelming. If your diagnosis is confirmed, contact a movement disorder specialist as soon as possible. A specialist can help you develop a strategy to delay the onset of more severe disease and manage symptoms you’re already experiencing.

Make lifestyle changes

Making lifestyle changes may also help you manage your symptoms.

Many people find their symptoms flare up during periods of stress. Adding relaxing activities to your daily routine like yoga or meditation may help you minimize flare-ups.

Some early research has found that exercise may help slow the progression of Parkinson’s by stimulating the production of a molecule called brain-derived neurotrophic factor in your brain.

Many gyms now offer boxing classes for people with Parkinson’s to help them manage their symptoms. Other forms of exercise are thought to be effective as well, but boxing has become a popular option.

Participate in clinical trials

Joining a clinical trial can help contribute to Parkinson’s research and may even help you with your symptoms by giving you access to state-of-the-art treatment.

You can find clinical trials in your area by searching the NIH database. The Michael J. Fox Foundation also offers a clinical trial matching tool on their website.

No single test can provide enough information for a doctor to diagnose Parkinson’s.

A doctor can diagnose Parkinson’s clinically by examining your symptoms and medical history. They will likely also recommend other tests, such as imaging or blood tests, to rule out conditions that can cause similar symptoms.

Parkinson’s gets worse over time, but its progression varies in different people. Many people are able to manage their symptoms for many years before experiencing debilitating symptoms.

Parkinson’s research is a rapidly growing field. Researchers are continuously improving their understanding of the disease and learning new and better ways to treat it.