Differences between Parkinson’s and essential tremor: how to tell them apart and when to see a doctor

• Parkinson’s and essential tremor can look the same at first; knowing the differences helps people seek medical attention in time, explain specialists from Mass General Brigham.

A tremor in the hands does not always mean the same thing. It can appear at rest or when you try to do something as everyday as writing or holding a glass. Understanding the differences between Parkinson’s and essential tremor is key to reading these symptoms correctly and knowing when to seek medical attention.

According to the Parkinson’s Foundation, more than 10 million people live with the disease worldwide. Even so, essential tremor is considerably more frequent, according to estimates. Parkinson’s, however, tends to cause more concern because it is progressive and because of the impact it can have on quality of life.

The challenge is that, in many cases, the early symptoms can look similar. That confusion can delay medical attention and, with it, the start of proper treatment.

“How well treatments work can depend on how soon a diagnosis is made,” explains Dr Rees Cosgrove, a neurosurgeon at Mass General Brigham.

Parkinson’s vs essential tremor: what really causes them

Although both disorders affect movement, they do not have the same cause. Understanding this point is essential to grasp why they behave differently and call for different approaches.

Parkinson’s disease develops when certain brain cells stop producing dopamine, a substance that is essential for coordinating movement. As those levels fall, the brain loses precision and control over motor functions.

Essential tremor, by contrast, has no fully defined cause. The evidence, however, points to alterations in the cerebellum, the region of the brain in charge of coordination and balance.

That difference also shows in how often they occur. Essential tremor is considerably more common and can affect many more people than Parkinson’s, although the latter tends to have a greater impact on quality of life.

Characteristics of the tremor in Parkinson’s disease

One of the most important points in understanding the differences between Parkinson’s and essential tremor is when the tremor appears.

In Parkinson’s, the tremor usually appears when the person is at rest. That is, when they are not doing anything.

“Interestingly, the tremor decreases when a patient intentionally moves their arms or legs,” notes Dr Cosgrove.

Other characteristics of the Parkinson’s tremor include:

• Rhythmic, back-and-forth movement
• Frequently starting in the hands, but also in the jaw or feet
• Increasing in stressful situations

To this are added other symptoms such as:

• Slowness of movement (bradykinesia)
• Muscle stiffness
• Balance problems
• Difficulty walking or writing

How to tell essential tremor from Parkinson’s

Essential tremor shows up when the person is moving, not at rest. That is, it usually appears while doing everyday activities such as writing, eating or getting dressed.

“You may be eating or writing when your hands start to shake, and the tremor goes away when you stop moving,” explains the specialist.

Its main characteristics include:

• It appears during action
• It can affect the hands, the head or even the voice
• It tends to get worse with stress or lack of sleep
• It is generally not accompanied by other neurological symptoms

Identifying this pattern is key, since it makes it possible to tell it apart from Parkinson’s from the first signs and to guide the diagnosis better.

Risk factors to consider

Understanding the risk factors also helps identify these conditions.

With Parkinson’s, the risk rises if:

• You are over 60
• There is a family history
• You have been exposed to pesticides
• There are associated genetic factors

In the case of essential tremor:

• It can appear from the age of 40 or 50
• In 50% to 70% of cases it is hereditary

Diagnosis: why it can be complex

Identifying these conditions correctly is not always straightforward, especially in the early stages.

There is no single test that can diagnose Parkinson’s disease or essential tremor with certainty. Specialists therefore turn to a full neurological assessment, along with a review of clinical history and additional tests.

The most commonly used tools include:

• Blood tests
• CT scans
• MRI scans
• Functional brain studies

The challenge is that other neurological diseases can present similar symptoms. That means diagnosis requires clinical experience and careful assessment to avoid confusion.

Treatment: what options exist today

Although there is no cure, both conditions can be treated and controlled.

With Parkinson’s, treatments include:

• Medication to replace dopamine
• Physical, occupational and speech therapy
• Deep brain stimulation
• Focused ultrasound

With essential tremor:

• Medication to reduce the tremors
• Lifestyle changes (less caffeine, less stress)
• Adapted devices
• Brain stimulation in advanced cases

“We already have several effective treatments… and with research advancing quickly, we may well have new tools in the coming years,” says Dr Cosgrove.

When should you see a doctor?

Recognising the differences between Parkinson’s and essential tremor is no substitute for a medical assessment.

If you have persistent tremors, changes in movement or difficulty carrying out everyday activities, it is important to see a specialist.

An early diagnosis does not only improve symptom control, it can also slow the progression of the disease.

Because when it comes to the nervous system, understanding what is happening in your body can make the difference between uncertainty and timely treatment.