What are the vagus (or phrenic) nerves and what would cause it to become irritated resulting in prolonged hiccups? Treatments?

See answer. The vagus nerve is the 10th cranial nerve and interfaces with the parasympathetic nervous system. It enervates multiple areas in the body including the heart, diaphragm, and stomach. Hiccups can be caused by air swallowing (aerophagia), over distention of the stomach and alcohol..among other causes. For a discussion of causes and treatment please see: http://bit.ly/1KmgNlE.