Persistent hiccups as an unusual manifestation of hyponatremia.

In two patients, persistent hiccups were an unusual presenting manifestation of hyponatremia. Persistent hiccups occur in a variety of serious diseases, including metabolic and electrolyte disorders. They may cause the victim significant distress and may be refractory to most treatments. Hiccups lasting more than 24 hours require investigation for an underlying organic etiology, with hyponatremia included in the differential diagnosis.