Parkinson’s disease (PD) is a neurological disorder that causes symptoms such as tremors, slow movements, and muscle stiffness. These symptoms may overlap with symptoms of other conditions, making diagnosis hard.

PD is a neurological disorder that causes changes to muscle movement, and it can sometimes lead to behavioral and cognitive health concerns at late stages. The disease gets worse over time, eventually making it hard for people to walk and control their movements.

Other diseases share similar signs and symptoms with PD. Keep reading to learn more about what symptoms a person may have with PD, what conditions share similar characteristics, and how often PD may be misdiagnosed.

Researchers estimate that up to 1 million people in the United States are affected by PD. While each person’s experience is unique, there are certain symptoms that are characteristic of PD.

The four main symptoms include:

  • tremors in your head, jaw, arms, legs, and hands
  • stiffness in your muscles
  • slowness in movements
  • trouble with balance and coordination and falls

Symptoms usually start on one side of your body and tend to get worse over time. The rate of progression depends on the person, but it generally goes on to affect both sides of the body.

Additional symptoms:

Conditions that affect movement and muscle control may mimic PD. Most of these other conditions involve changes within neurons in your brain, but they each affect different areas of the brain.

While these conditions may be similar to PD, each has unique characteristics that may help with diagnosis.

Corticobasal syndrome

Corticobasal degeneration is a progressive (meaning it gets worse over time) neurological condition that causes shrinking in certain areas of your brain. It causes symptoms similar to those seen in PD, including trouble with balance and voluntary movements. People with this condition also may experience muscle spasms (myoclonus) and trouble swallowing.

Essential tremor

This condition was previously called benign essential tremor, and it may or may not be progressive. Essential tremor can be part of a neurological disease or a side effect of medications. Other times, the cause may be unknown. Symptoms include fine rhythmic muscle movements that may start on one side of your body (like PD) and later involve both sides.

Huntington’s disease

Huntington’s disease (HD) is a genetically inherited disorder that causes changes to the neurons in your brain. Symptoms include balance and coordination difficulties, behavior changes, and cognitive health concerns.

People with HD may have a movement disorder called chorea. The movements of people with chorea are large jerky movements, but the movements of those with PD are small, fast movements. And, unlike with PD, doctors can also use blood tests for genetic screening to diagnose HD.

Lewy body dementia

Lewy body dementia (LBD) can be divided into dementia with Lewy bodies and PD dementia. People with these conditions experience similar changes to their brain and, as a result, similar symptoms. The main difference between the two is the time of onset of these symptoms.

With LBD, symptoms that affect cognition (thinking) occur around the same time as the symptoms that involve movement. With Parkinson’s dementia, impaired cognition begins at late stages of the disease, usually after the movement symptoms have significantly worsened.

Multiple system atrophy

Multiple system atrophy (MSA) is a progressive neurological disorder that causes severe shrinking of certain areas of your brain. MSA affects your movement and nervous system. Symptoms are similar to those people experience with PD.

In particular, people with MSA may have tremor, rigid muscles, and coordination difficulties. They may also have trouble walking and speaking.

There are two types of MSA, one of which is called parkinsonian type (MSA-P) because it closely mimics PD. That said, MSA-P progresses more quickly than PD.

Normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) happens when there’s a buildup of cerebrospinal fluid (CSF) on your brain. The pressure can cause symptoms such as dementia, trouble walking, and urinary incontinence. It can mimic other conditions, such as Alzheimer’s disease and PD.

Unlike those progressive diseases, though, NPH generally gets better after the surgical placement of a shunt to redirect the excess CSF.

Progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is also often misdiagnosed as PD. This condition causes similar muscle stiffness, coordination issues, and characteristic slow movement seen early on in PD. PSP also involves limited eye movements called supranuclear palsy, but Parkinson’s doesn’t.

Another key difference is that PSP progresses more quickly than PD. While the treatments are also similar, people with PSP don’t generally respond to medications as well as people with PD.

Drug-induced parkinsonism

Taking certain medications — neuroleptics, dopamine-blocking drugs, etc. — may cause drug-induced parkinsonism (DIP). Symptoms include tremors, muscle rigidity, and trouble walking. A major difference is that 90% of people with DIP get better after stopping the drug that’s causing their symptoms.

Other mimics

There’s no laboratory test (blood test, for example) that can diagnose PD.

Diagnosis is made after a healthcare professional performs physical and neurological exams and discusses your symptoms and medical history. In some cases, a doctor may suggest taking medications for PD. If these medications ease your symptoms, this can also help confirm a diagnosis.

What treatments are available for PD?

Various medications can be used to treat PD. The main treatment of choice is a drug called levodopa. Deep brain stimulation is another option for some people and involves surgery.

Does PD get better with treatment?

There’s currently no cure for PD. Treatments can help to ease symptoms and improve your quality of life.

Is it common to be misdiagnosed?

Diagnosis can be tricky when symptoms overlap between different conditions. A recent poll shows that slightly more than 1 in 4 people with PD are misdiagnosed. Beyond that, women are more likely to be misdiagnosed than men.

If you experience symptoms such as muscle stiffness or tremors, contact a doctor. While diagnosing PD can be difficult, there are tests that may help rule out similar conditions.

It may take some time to get a correct diagnosis. If something doesn’t feel right, share your concerns with a doctor until you find a treatment that works best for you.