The aim of the SINERGE study was to assess the impact of nocturnal heartburn on quality of life, sleep, and productivity. Ambulatory patients >/=18 years old and classified as defined cases of nocturnal heartburn (n=337), nonnocturnal heartburn (n=139), uncontrolled hypertension (n=198), and symptomatic depression (n=104) were included in this cross-sectional study. Information on age, gender, body mass index, and comorbidity was collected and the following validated questionnaires were applied: SF-12, Pittsburgh Sleep Quality Index, and Work Productivity and Activity Impairment questionnaire. The prevalence of primary care consultation for heartburn and nocturnal heartburn was 4.7% and 1.9%, respectively. Health-related quality of life, sleep, and productivity were significantly impaired in patients with frequent nocturnal heartburn symptoms as compared with those of the patients without nocturnal symptoms or patients with hypertension. Nocturnal heartburn poses a considerable burden for the sufferer because of the impact on quality of life, sleep, and daily activities.