Former U.S. Federal Reserve Chairman Alan Greenspan has died at the age of 100, according to reports. The CNBC report confirmed his passing and highlighted his long and influential career in global economics and U.S. monetary policy. Following the news, public attention has also turned toward discussions around age-related illnesses, particularly Parkinson’s disease, as readers search for background health information linked to elderly public figures.ALSO READ: Woman accused of making anti-Islam remarks in viral store video raises over $85,000 What Is Parkinson Disease?Parkinson’s disease is a progressive neurological disorder that primarily affects movement. It develops when nerve cells in the brain that produce dopamine gradually become damaged or die. Dopamine is responsible for controlling smooth and coordinated muscle movements. Parkinson's is the second-most common neurodegenerative disease after Alzheimer's disease.Over time, the loss of dopamine leads to symptoms that interfere with daily activities, including walking, speaking, and balance control. According to Parkinson.org:Parkinson’s disease affects more than 1.1 million people in the U.S. Nearly 90,000 people are newly diagnosed each year. The Parkinson’s Foundation studies reveal that PD prevalence and incidence increase with age, affect men 1.5 times more than women and are higher in regions like the Rust Belt, Southern California and Florida.ALSO READ: NYC coffee shop bans pro-Israel politician Dan Goldman, issues him refundParkinson Disease SymptomsCommon symptoms include:Tremors, often starting in the handsMuscle stiffnessSlowed movement (bradykinesia)Impaired balance and coordinationChanges in speech and writingAs the condition progresses, symptoms may become more severe and affect independence.What Causes Parkinson Disease?The exact cause of Parkinson’s disease is still not fully understood. However, researchers believe it is linked to a combination of genetic and environmental factors.Possible causes and risk factors include:Genetic mutations in certain casesExposure to toxins or pesticidesAge-related degeneration of brain cellsReduced dopamine productionIn most cases, the disease develops without a clear single trigger.Parkinson Disease ICD-10 CodeIn medical classification systems, Parkinson’s disease is listed under the ICD-10 code G20. This coding is used by healthcare professionals for diagnosis, billing, and research purposes. Stages of Parkinson DiseaseParkinson’s disease is typically divided into five stages:Stage 1: Mild symptoms on one side of the bodyStage 2: Symptoms affect both sides, but balance is intactStage 3: Noticeable balance issues and slowed movementStage 4: Severe symptoms requiring assistanceStage 5: Advanced stage with significant mobility lossEach stage reflects gradual progression over time. What Causes Parkinson’s and Why It DevelopsScientists continue to study why Parkinson’s disease develops in some individuals and not others. Aging remains the strongest known risk factor, while brain changes involving dopamine-producing neurons are central to the condition.Although no cure exists yet, treatments focus on managing symptoms and improving quality of life through medication, therapy, and lifestyle adjustments. Parkinson diseaseParkinson’s disease remains one of the most researched neurological disorders, especially as global life expectancy increases. Awareness of symptoms, causes, and progression can help with early recognition and better management of the condition.