Esophageal pH monitoring, indications, and methods.

Symptomatic gastroesophageal reflux disease (GERD) is a common problem that affects a substantial proportion of the American population. It is estimated that the symptoms of GERD may afflict 40% to 45% of Americans each month. The diagnosis of GERD can be difficult, as its symptoms vary from typical symptoms like heartburn to atypical symptoms such as hoarseness, coughing, and chest pain.