Parkinson's disease is a progressive neurodegenerative disorder primarily affecting movement, caused by the degeneration of dopamine-producing neurons in the substantia nigra. It is clinically significant due to its impact on motor function, leading to symptoms such as tremors, rigidity, and bradykinesia, which can severely affect quality of life. A key association is the development of non-motor symptoms, such as depression and cognitive impairment, which complicate management.