The term 'non-ulcer dyspepsia' lacks a generally accepted definition. A broad spectrum of symptoms could be included under this heading. Therefore, a subclassification with strict and reproducible lines of demarcation is needed. The aim of a recently concluded study was to delineate the category of patients who suffer from chronic or recurrent epigastric pain without symptoms of Irritable Bowel Syndrome and without any anatomical correlates. In order to emphasize the distinction between the studied condition and the less well-defined diagnosis of non-ulcer-dyspepsia we have proposed an alternative designation, "Epigastric Distress Syndrome". The admixture of initially overlooked organic diseases seems to be almost negligible when strict criteria are used for the diagnosis. Gastric acid is probably not involved in the etiology but psychological factors seem to be crucial for the development of this condition. When specifically asked, about every third person report abdominal symptoms. Their complaints are commonly referred to as dyspepsia, but the term lacks a generally accepted definition. In practice, every possible symptom arising from the gastrointestinal tract except jaundice and bleeding could be gathered under this heading. A large number of organic diseases are conceivable causes of dyspepsia, but conditions with presumed functional etiology dominate, at least in outpatient care. In fact, the clinical diagnosis of 'gastritis', which is used to describe upper abdominal complaints without any apparent organic causes, accounts for 2% of all outpatient consultations in Sweden, and it is by far the most commonly used gastroenterological diagnosis in this country.