What are the Stages of Parkinson's Disease?

If you've been diagnosed with Parkinson's disease, it's natural to wonder how the disease may change over time. Everyone has a different experience with Parkinson's, but it can still be helpful to know the general stages of Parkinson's that doctors and researchers use to understand disease progression.

Doctors and researchers define the different stages of Parkinson's by a few different factors:

• Whether symptoms affect one or both sides of the body
• How much Parkinson's affects your balance
• Level of independence in daily living activities

Some doctors may refer to the stages of Parkinson's as the Hoehn and Yahr stages. This tracking method, developed in the 1960s, follows the below stages:

Stage one:

In stage one, Parkinson's disease symptoms only affect one side of the body. For example, you may only experience tremor in your right hand, or one leg may feel stiffer than the other.

Tremor is often the first symptom that patients notice, but other symptoms such as muscle stiffness may also appear first. In fact, researchers believe that some Parkinson's symptoms may appear years before diagnosis. Loss of smell and REM sleep behavior disorder, in particular, can precede other symptoms by years.

There is no objective test, such as a blood test, that's able to diagnose Parkinson's disease. Instead, neurologists and movement disorder specialists use a series of questions and in-office tests to make a diagnosis. Sometimes, a patient may not receive a definitive diagnosis until they begin taking medication and find that it helps their symptoms. 

Because of how difficult it can be to diagnose Parkinson's, some patients are not diagnosed in stage one.

Stage two:

In the second stage of Parkinson's disease, patients experience symptoms on both sides of the body, but balance is not impaired. Symptoms at this stage may include facial masking, which reduces facial expressions, a softer voice, and stiffness and muscle rigidity that can lead to a stooped posture. People with Parkinson's may also experience slowed movement in general. Those at this stage continue to live an independent life. Stages one and two are considered to be early-stage Parkinson's.

Stage three:

Stage three includes all of the symptoms of stages one and two, with the addition of loss of balance. Slowness of movement may also be more pronounced at this stage.

As Parkinson's progresses, it becomes more difficult to make the automatic motions needed to catch oneself from falling. Falls are common at stage three.

Sometimes, Parkinson's symptoms such as muscle stiffness are mistaken for signs of normal aging. Patients may not receive an official diagnosis until reaching stage three. At this stage, physicians may check reflexes by standing behind the patient and pulling the shoulders gently to see if the patient has trouble staying balanced – without letting the patient fall, of course.

People with Parkinson's at stage three are still independent in their daily living activities, such as getting dressed, brushing their teeth, and eating.

Stage four:

Stages four and five in Parkinson's are defined by whether or not the person with Parkinson's is still able to live independently. If the patient is still able to live alone or complete daily living tasks without assistance, they're considered to be in stage three. Once a patient needs help with these tasks, they have moved into stage four.

At stage four, the person with Parkinson's can still stand up unassisted, and may use a walker to get around. They may still need help with some daily living tasks. Stages four and five are considered late-stage Parkinson's.

Stage five:

This is the most advanced stage of Parkinson's disease. Someone at stage five is no longer able to walk or stand unassisted. They may fall when standing or turning around. Those at this stage require around-the-clock assistance with daily activities, and to help prevent falls. 

While Parkinson's disease is a movement disorder, it also affects the brain. Not everyone with Parkinson's experiences neurological symptoms such as psychosis (delusions) or dementia, but some do, especially in the later stages of the disease.

No two experiences with Parkinson's are the same. While Parkinson's symptoms get worse with time, not everyone experiences all symptoms. Medication can help improve many of the symptoms of Parkinson's, though the gold standard treatment tends to become less effective as the underlying disease worsens. New treatments are in development all the time for both movement-related and non-movement related Parkinson's symptoms, and to help current treatment options work better.