What Is Parkinson’s?

Parkinson’s disease is a progressive neurological condition that affects movement, balance, and many everyday functions. It develops when nerve cells in a part of the brain that produces dopamine begin to deteriorate. Dopamine helps control smooth, coordinated movement, so as levels decline, symptoms gradually appear and change over time.

According to the National Institute of Neurological Disorders and Stroke, Parkinson’s symptoms usually develop slowly and may begin subtly, often affecting one side of the body first.

Common Symptoms of Parkinson’s

Parkinson’s symptoms are often divided into motor symptoms (movement-related) and non-motor symptoms (affecting other body functions).

Movement (Motor) Symptoms

• Tremor, often starting in one hand at rest
• Slowness of movement (bradykinesia)
• Muscle stiffness (rigidity)
• Balance and posture problems
• Smaller handwriting or reduced facial expression

These symptoms may start mildly and gradually become more noticeable over time.

According to clinical reviews published in the National Center for Biotechnology Information, tremor, rigidity, and bradykinesia are considered the three core motor features used in diagnosing Parkinson’s.

Non-Motor Symptoms

Some symptoms can appear years before movement changes, including:

• Loss of smell
• Sleep problems
• Constipation
• Depression or anxiety
• Fatigue
• Mild memory or thinking changes

These early signs are sometimes overlooked but are increasingly recognized as part of Parkinson’s.

Researchers note that non-motor symptoms may appear in early stages due to changes in brain chemistry before noticeable movement symptoms begin.

What Causes Parkinson’s?

The exact cause of Parkinson’s is not fully understood. Most experts believe it is caused by a combination of aging, genetics, and environmental factors.

A key feature of Parkinson’s is the loss of dopamine-producing neurons in a brain region called the substantia nigra. As these cells decline, movement becomes more difficult.

According to research published in the journal Nature Reviews Neuroscience, Parkinson’s is also associated with the buildup of abnormal proteins called alpha-synuclein, which form structures known as Lewy bodies in the brain.

Other possible contributing factors include:

• Genetics (family history in some cases)
• Environmental exposures
• Inflammation in the brain
• Mitochondrial dysfunction

Most people with Parkinson’s develop the condition without a single identifiable cause.

How Parkinson’s Progresses

Parkinson’s typically develops slowly over many years, and progression varies from person to person. Some people experience gradual changes, while others may notice symptoms more quickly.

Early Stage

• Mild tremor or stiffness
• Symptoms on one side of the body
• Small changes in walking or posture
• Non-motor symptoms may appear

Middle Stage

• Increased stiffness and slowness
• Balance issues may develop
• Daily tasks take longer
• Medications become more important

Advanced Stage

• Greater mobility challenges
• Increased fall risk
• Speech or swallowing difficulty
• More noticeable non-motor symptoms

According to clinical summaries from the National Center for Biotechnology Information, Parkinson’s progression varies widely, and many individuals live independently for years with proper treatment and lifestyle adjustments.

Important to Know

Although Parkinson’s is progressive, treatments can help manage symptoms and improve quality of life. These may include:

• Medications
• Exercise and physical therapy
• Nutrition and lifestyle changes
• Speech and occupational therapy
• Advanced treatments in some cases

Early education and consistent routines can make a meaningful difference over time.