Until recently, the finding of erosive esophagitis in patients with chronic heartburn was thought to indicate more severe gastroesophageal reflux disease. However, recent data suggests that this is not necessarily true. Seventy-five percent of patient's chronic heartburn have moderate to severe symptoms, regardless of the presence or absence of esophagitis. Nonerosive reflux disease (NERD) is characterized by heartburn symptoms for at least 3 months with no evidence of esophagitis. Patients with NERD are similar to patients with esophagitis in symptom severity, quality of life scores, and response to anti-reflux therapy. There are probably 3 distinct groups of NERD patients, those with pathologic reflux, those with a heightened sensitivity to physiologic reflux and those with other medical problems mistaken for reflux. This article discusses the 3 clinical scenarios.