Hiatus hernia Hiatal hernia A tendency for the upper part of the stomach to herniate into the thorax because of a weakness of the esophageal hiatus, which is the hole in the diaphragm through which the esophagus passes. Hiatus hernia can be asymptomatic or can lead to acid reflux symptoms (heartburn). MeSH:D006551 HP:0002036 Stomach hernia peter The presence of a hernia in which the upper part of the stomach, i.e., mainly the gastric cardia protrudes through the diaphragmatic esophageal hiatus. MEDDRA:10020028 UMLS:C0019291 2008-02-20T11:28:00Z human_phenotype SNOMEDCT:84089009 Hernia