Parkinson's disease is a progressive neurodegenerative disorder characterized by tremors, rigidity, bradykinesia, and impaired balance. It is caused by the loss of dopamine-producing neurons in the substantia nigra. The disease mostly affects older adults and its prevalence increases with age. While the exact cause is unknown, potential risk factors include genetics, environmental toxins, and brain injuries. There is no cure for Parkinson's, but treatment aims to improve symptoms through medication and physical therapy.