A client with Parkinson's disease complains of feeling dizzy upon standing. Which non-motor complication is suspected?

Rationale: A. Tremor in Parkinson’s disease is a classic motor symptom, often presenting as a resting tremor in the hands, fingers, or jaw. It occurs independently of posture and does not typically cause lightheadedness, dizziness, or syncope upon standing. While tremor can interfere with fine motor tasks, it is not related to autonomic dysfunction or blood pressure changes. B. High blood pressure generally does not cause dizziness upon standing. In fact, hypertension may coexist with Parkinson’s disease but is not responsible for orthostatic symptoms. Dizziness related to blood pressure in PD is usually caused by hypotension (low blood pressure), not elevated blood pressure. Focusing on hypertension would misdirect treatment efforts in this scenario. C. Orthostatic hypotension (OH) is a non-motor complication of PD, resulting from autonomic nervous system dysfunction. When a patient stands, blood pressure fails to adjust appropriately, leading to decreased cerebral perfusion. Symptoms include dizziness, lightheadedness, blurred vision, or syncope, which can cause falls and impair functional independence. OH can be exacerbated by dopaminergic therapy, dehydration, prolonged bed rest, and age-related vascular changes. D. Bradykinesia refers to slowness of voluntary movements and affects gait, speech, facial expression, and fine motor activities. It is a motor symptom, not an autonomic one, and does not directly cause dizziness or lightheadedness when changing positions. While bradykinesia may contribute to falls due to slow reactions, the primary cause of postural dizziness in this scenario is OH.