Functional dyspepsia (FD)Functional dyspepsia (FD) is a common functional gastrointestinal disorder characterized by chronic upper abdominal discomfort in the absence of identifiable organic disease. In clinical practice, FD is frequently associated with comorbidities, including psychiatric disorders, other functional gastrointestinal disorders (FGIDs) such as irritable bowel syndrome (IBS) and gastroesophageal reflux disease (GERD), and other functional somatic syndromes (FSS) such as functional headache. These comorbid conditions can complicate both diagnosis and management. Additionally, FD shares overlapping symptoms with Helicobacter pylori-associated dyspepsia (HpD), posing a challenge for accurate differential diagnosis. This article presents clinical cases illustrating common patterns of FD: (1) FD with comorbid mental disorders, (2) FD with coexisting FGIDs, (3) FD with comorbid FSS, and (4) differential diagnosis between FD and HpD.