Exhaled Breath Condensate pH in Patients With Cough Caused by Gastroesophageal Reflux

Cough is the most common complaint for which patients seek medical attention in the United States, accounting for approximately 1 billion dollars in health care expenses annually. Gastroesophageal reflux disease (GERD) is the sole cause of chronic cough in up to 20-40% of all cases. The majority of these patients with GERD-induced cough have no classic "heartburn" symptoms, so this important cause of cough can thus be difficult to detect. Our hypothesis is that changes in exhaled breath condensate (EBC) pH can be used as a sensitive and non-invasive marker to identify subjects with cough caused by acid reflux.