Functional dyspepsia is highly variable in its clinical presentation and multifactorial in its underlying causes. Since many of the symptoms included in the definition of dyspepsia are intuitively suggestive of different pathogenic mechanisms, it has been proposed that patients with functional dyspepsia be divided into distinct dyspepsia sub-groups according to symptom clusters. The goal was to classify patients more homogeneously for research purposes as well as to target treatment. However, recent epidemiological, pathophysiological, and clinical studies indicate that a priori definitions based on the presence/absence of symptoms or clusters of symptoms have no clinical utility due to the considerable overlap between symptoms, as well as the poor correlation between pathogenic factors and responses to treatment. Attention is now focused on identifying predominant symptoms. Recent studies suggest that the analysis of predominant symptoms, demographic features, and overlapping digestive syndromes can help to identify dyspepsia sub-groups with different underlying pathophysiological features and aid in selecting appropriate treatment. The utility of this approach has been demonstrated in gastro-oesophageal reflux disease, which can be reliably diagnosed and managed on the basis of the presence and severity of the predominant symptom, heartburn. It is likely that precise symptom definitions and history-taking will be of pivotal importance in management strategies for functional dyspepsia.