PURPOSE OF REVIEW: Parkinson disease (PD) is a common neurodegenerative movement disorder, the prevalence of which is rising as the world population ages. It may present with motor and nonmotor symptoms, and symptomatic treatment significantly improves quality of life. This article provides an overview of the workup and differential diagnosis for PD and reviews genetic and environmental risk factors and current treatments.RECENT FINDINGS: Novel treatments for the motor (eg, fluctuations and off times) and nonmotor (eg, hallucinations and orthostatic hypotension) complications of PD have been approved in recent years. In addition, with recent advances in our understanding of the genetics of PD, significant research is focusing on identifying at-risk populations and introducing genetically targeted interventions (precision medicine). SUMMARY: PD is a heterogeneous neurodegenerative movement disorder. Affected individuals may receive substantial symptomatic relief from nonpharmacologic, pharmacologic, and surgical interventions. Although no intervention to modify the progression of PD is currently available, precision medicine and modulation of the immune system are a major focus of ongoing research.