<P> Higher in the abdomen, an (internal) "diaphragmatic hernia" results when part of the stomach or intestine protrudes into the chest cavity through a defect in the diaphragm . </P> <P> A hiatus hernia is a particular variant of this type, in which the normal passageway through which the esophagus meets the stomach (esophageal hiatus) serves as a functional "defect", allowing part of the stomach to (periodically) "herniate" into the chest . Hiatus hernias may be either "sliding", in which the gastroesophageal junction itself slides through the defect into the chest, or non-sliding (also known as para-esophageal), in which case the junction remains fixed while another portion of the stomach moves up through the defect . Non-sliding or para-esophageal hernias can be dangerous as they may allow the stomach to rotate and obstruct . Repair is usually advised . </P> <P> A congenital diaphragmatic hernia is a distinct problem, occurring in up to 1 in 2000 births, and requiring pediatric surgery . Intestinal organs may herniate through several parts of the diaphragm, posterolateral (in Bochdalek's triangle, resulting in Bochdalek's hernia), or anteromedial - retrosternal (in the cleft of Larrey / Morgagni's foramen, resulting in Morgagni - Larrey hernia, or Morgagni's hernia). </P> <P> Since many organs or parts of organs can herniate through many orifices, it is very difficult to give an exhaustive list of hernias, with all synonyms and eponyms . The above article deals mostly with "visceral hernias", where the herniating tissue arises within the abdominal cavity . Other hernia types and unusual types of visceral hernias are listed below, in alphabetical order: </P>

What is the relation between heredity and hernia