The prevalence of hiatal hernia can only be estimated, because most of these hernias cause mild or no symptoms and diagnostic criteria may vary. One study used noncontrast computed tomography (CT) to identify hiatal hernias in a large sample of asymptomatic adults (ages 53 to 94 years); they reported a prevalence of 9.9%, but noted CT may be insensitive to small, sliding hernias.[2]Kim J, Hiura GT, Oelsner EC, et al. Hiatal hernia prevalence and natural history on non-contrast CT in the multi-ethnic study of atherosclerosis (MESA). BMJ Open Gastroenterol. 2021 Mar;8(1):e000565.
https://bmjopengastro.bmj.com/content/8/1/e000565
http://www.ncbi.nlm.nih.gov/pubmed/33731384?tool=bestpractice.com
Higher rates are reported among symptomatic populations. In one retrospective study of patients who had undergone endoscopy at a tertiary care hospital, the prevalence of hiatal hernia was 28.9%.[3]Alsahafi MA, Alajhar NA, Almahyawi AO, et al. The prevalence and risk factors for hiatal hernia among patients undergoing endoscopy: a retrospective analysis. Saudi Med J. 2023 May;44(5):509-12.
https://smj.org.sa/content/44/5/509
http://www.ncbi.nlm.nih.gov/pubmed/37182923?tool=bestpractice.com
The prevalence may be lower in Asian-Americans.[2]Kim J, Hiura GT, Oelsner EC, et al. Hiatal hernia prevalence and natural history on non-contrast CT in the multi-ethnic study of atherosclerosis (MESA). BMJ Open Gastroenterol. 2021 Mar;8(1):e000565.
https://bmjopengastro.bmj.com/content/8/1/e000565
http://www.ncbi.nlm.nih.gov/pubmed/33731384?tool=bestpractice.com
The incidence of symptomatic cases of hiatal hernia is closely related to the diagnosis of gastroesophageal reflux disease (GERD), as these two conditions are closely (but not completely) correlated.[3]Alsahafi MA, Alajhar NA, Almahyawi AO, et al. The prevalence and risk factors for hiatal hernia among patients undergoing endoscopy: a retrospective analysis. Saudi Med J. 2023 May;44(5):509-12.
https://smj.org.sa/content/44/5/509
http://www.ncbi.nlm.nih.gov/pubmed/37182923?tool=bestpractice.com
[4]Petersen H, Johannessen T, Sandvik AK, et al. Relationship between endoscopic hiatus hernia and gastroesophageal reflux symptoms. Scand J Gastroenterol. 1991 Sep;26(9):921-6.
http://www.ncbi.nlm.nih.gov/pubmed/1947783?tool=bestpractice.com
The precise incidence of treated cases of GERD in large populations is difficult to verify. According to one meta-analysis, the pooled global prevalence of GERD is about 14%, with significant regional variation.[5]Nirwan JS, Hasan SS, Babar ZU, et al. Global prevalence and risk factors of gastro-oesophageal reflux disease (GORD): systematic review with meta-analysis. Sci Rep. 2020 Apr 2;10(1):5814.
https://www.nature.com/articles/s41598-020-62795-1
http://www.ncbi.nlm.nih.gov/pubmed/32242117?tool=bestpractice.com
Among all hiatal hernias, the sliding (type I) hernia is by far the most common, accounting for 85% to 95% of cases. For paraesophageal hernias (types II-IV), type III (mixed, paraesophageal with a sliding component) is the most common.[1]Society of American Gastrointestinal and Endoscopic Surgeons. Guidelines for the management of hiatal hernia. Apr 2013 [internet publication].
http://www.sages.org/publications/guidelines/guidelines-for-the-management-of-hiatal-hernia
[6]Roman S, Kahrilas PJ. The diagnosis and management of hiatus hernia. BMJ. 2014 Oct 23;349:g6154.
http://www.ncbi.nlm.nih.gov/pubmed/25341679?tool=bestpractice.com