Which of the following is NOT considered a cause of dysphagia due to physical obstructions?

Dysphagia, or difficulty swallowing, can arise from various causes, and physical obstructions are a significant category. Tumors and abnormalities can create obstructions in the esophagus or throat that directly impede the normal swallowing process. Conditions like a cleft lip or palate also result in anatomical anomalies that can interfere with swallowing mechanics due to their structural nature.

In contrast, Alzheimer's disease is primarily a neurological condition that affects cognitive function and can indirectly lead to swallowing difficulties. However, it does not cause physical obstructions in the airway or esophagus. The challenges faced by individuals with Alzheimer's typically relate more to impaired function and coordination rather than a physical barrier obstructing the swallowing pathway. This distinction underlines the difference between physical causes of dysphagia and those that are functional or cognitive in nature, which is why Alzheimer's is identified as not being a cause of dysphagia due to physical obstructions.