BEST PRACTICE ADVICE 1: A diagnosis of functional heartburn should be considered when retrosternal burning pain or discomfort persists despite maximal (double-dose) proton pump inhibitor (PPI) therapy taken appropriately before meals during a 3-month period. BEST PRACTICE ADVICE 2: A diagnosis of functional heartburn requires upper endoscopy with esophageal biopsies to rule out anatomic and mucosal abnormalities, esophageal high-resolution manometry to rule out major motor disorders, and pH monitoring off PPI therapy (or pH-impedance monitoring on therapy in patients with proven gastroesophageal reflux disease [GERD]), to document physiologic levels of esophageal acid exposure in the distal esophagus with absence of reflux-symptom association (ie, negative symptom index and symptom association probability). BEST PRACTICE ADVICE 3: Overlap of functional heartburn with proven GERD is diagnosed according to Rome IV criteria when heartburn persists despite maximal PPI therapy in patients with history of proven GERD (ie, positive pH study, erosive esophagitis, Barrett's esophagus, or esophageal ulcer), and pH impedance testing on PPI therapy demonstrates physiologic acid exposure without reflux-symptom association (ie, negative symptom index and symptom association probability). BEST PRACTICE ADVICE 4: PPIs have no therapeutic value in functional heartburn, the exception being proven GERD that overlaps with functional heartburn. BEST PRACTICE ADVICE 5: Neuromodulators, including tricyclic antidepressants, selective serotonin reuptake inhibitors, tegaserod, and histamine-2 receptor antagonists have benefit as either primary therapy in functional heartburn or as add-on therapy in functional heartburn that overlaps with proven GERD. BEST PRACTICE ADVICE 6: Based on available evidence, acupuncture and hypnotherapy may have benefit as monotherapy in functional heartburn, or as adjunctive therapy combined with other therapeutic modalities. BEST PRACTICE ADVICE 7: Based on available evidence, anti-reflux surgery and endoscopic GERD treatment modalities have no therapeutic benefit in functional heartburn and should not be recommended.