Hemorrhoids pathophysiology: Difference between revisions

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Latest revision as of 22:03, 29 July 2020

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Overview

Hemorrhoids develop due to a combination of genetic predisposition (weak rectal veins) and certain diet and defecation habits.

Pathophysiology

Hemorrhoids can be internal and external.

Internal hemorrhoids are located above the dentate line and they occur due to dilatation of the superior hemorrhoidal plexus.^[1]

The connective tissue over the superior hemorrhoidal plexus is innervated via visceral nerves and thus it is pain insensitive.

External hemorrhoids are located below the dentate line and occur due to dilatation of the inferior hemorrhoidal plexus.^[2]

The first step in the pathogenesis of either type of hemorrhoids is weakening of the surrounding connective tissue and vein wall. All the risk factors (old age, pregnancy, portal hypertension, etc) lead to aggravating this weakness or add more pressure from within the vein. ^[3]^[4]

Increased tone of the internal anal sphincter causing the feces to press the hemorrhoid against the muscle and thus decreasing venous return and aggravating the symptoms.^[5]

The arteriovenous anastomosis may play a role in the development of hemorrhoids. This is supported by the fact that some hemorrhoids improve after ligating the connecting arteries.^[6]

The redundant bulging mucosa is easily injured causing bleeding. The blood is usually bright red reflecting high oxygen content due to the proximity of AV anastomosis.

Gross pathology

External hemorrhoids appear on inspection of the anal verge as skin tags or strangulated or free prolapsed veins.
Internal hemorrhoids appear as bluish bulgings of the veins in the mucosa.

By Dr. Joachim Guntau - www.Endoskopiebilder.de, CC BY-SA 3.0, httpscommons.wikimedia.orgwindex.phpcurid=18660152	By Dr. Joachim Guntau - www.Endoskopiebilder.de, CC BY-SA 3.0, httpscommons.wikimedia.orgwindex.phpcurid=18660115
By Tmalonetn - Own work, CC BY-SA 3.0, httpscommons.wikimedia.orgwindex.phpcurid=10358212	By Internet Archive Book Images - httpswww.flickr.comphotosinternetarchivebookimages14784684835Source book page httpsarchive.orgstreamdiseasesofrectum00gantdiseasesofrectum00gant-pagen490mode1up, No restrictions, ht

References

↑ Guttenplan M (2017). "The Evaluation and Office Management of Hemorrhoids for the Gastroenterologist". Curr Gastroenterol Rep. 19 (7): 30. doi:10.1007/s11894-017-0574-9. PMID 28567655.
↑ "Causes of Hemorrhoids". Mayo Clinic. Nov 28, 2006. Retrieved 2007-12-07.
↑ Huang YT (2006). "[Consideration on the pathogenesis of hemorrhoids]". Zhonghua Wai Ke Za Zhi (in Chinese). 44 (15): 1019–21. PMID 17074235.
↑ Le Quellec A, Bories P, Rochon JC, Garrigues JM, Poirier JL, Michel H (1988). "[Portal hypertension and hemorrhoids. Cause effect relationship?]". Gastroenterol. Clin. Biol. (in French). 12 (8–9): 646–8. PMID 3265119.
↑ Burney RE (November 2005). "Hemorrhoids". University of Michigan Health System. Retrieved 2007-11-28.
↑ Harms R (Nov 3, 2007). "Hemorrhoids during pregnancy: Treatment options". MayoClinic. Retrieved 2007-11-28.

Template:WH Template:WS

[pmid28567655-1] Guttenplan M (2017). "The Evaluation and Office Management of Hemorrhoids for the Gastroenterologist". Curr Gastroenterol Rep. 19 (7): 30. doi:10.1007/s11894-017-0574-9. PMID 28567655.

[2] "Causes of Hemorrhoids". Mayo Clinic. Nov 28, 2006. Retrieved 2007-12-07.

[pmid17074235-3] Huang YT (2006). "[Consideration on the pathogenesis of hemorrhoids]". Zhonghua Wai Ke Za Zhi (in Chinese). 44 (15): 1019–21. PMID 17074235.

[pmid3265119-4] Le Quellec A, Bories P, Rochon JC, Garrigues JM, Poirier JL, Michel H (1988). "[Portal hypertension and hemorrhoids. Cause effect relationship?]". Gastroenterol. Clin. Biol. (in French). 12 (8–9): 646–8. PMID 3265119.

[titleHemorrhoids-5] Burney RE (November 2005). "Hemorrhoids". University of Michigan Health System. Retrieved 2007-11-28.

[titleHemorrhoids_during_[[pregnancy]]:_Treatment_options_-_MayoClinic.com-6] Harms R (Nov 3, 2007). "Hemorrhoids during pregnancy: Treatment options". MayoClinic. Retrieved 2007-11-28.

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[2]

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[4]

[5]

[6]

@@ Line 1: / Line 1: @@
 __NOTOC__
 {{Hemorrhoids}}
 {{CMG}}; {{AE}}{{AY}}
 ==Overview==
+Hemorrhoids develop due to a combination of [[genetic predisposition]] (weak rectal [[veins]]) and certain diet and defecation habits.
 ==Pathophysiology==
-The pathophysiology of hemorrhoids includes genetic predisposition (weak rectal vein walls and/or valves), straining during [[bowel]] movements, and too much pressure on the rectal veins due to poor muscle tone or poor posture. Similarly, sitting for prolonged periods of time can cause hemorrhoids. [[Hypertension]], particularly in the [[portal vein]], can also cause hemorrhoids because of the connections between the portal vein and the [[vena cava]] which occur in the rectal wall - known as [[portocaval anastomoses]].<ref>{{cite web |title=Causes of Hemorrhoids |url=http://www.mayoclinic.com/health/hemorrhoids/DS00096/DSECTION=3 |date=Nov 28, 2006  |publisher=Mayo Clinic |accessdate=2007-12-07}}</ref>
-Additional factors that can influence the course of hemorrhoids (mostly by increasing rectal vein pressure), especially for those with a genetic predisposition, are [[obesity]] and a [[sedentary lifestyle]].
+*Hemorrhoids can be internal and external.
-Increased straining during bowel movements, (e.g. [[constipation]], [[diarrhea]]) may lead to hemorrhoids. <ref name="titleHemorrhoids during pregnancy: Treatment options - MayoClinic.com">{{cite web |author=Harms R |title=Hemorrhoids during pregnancy: Treatment options |url=http://www.mayoclinic.com/health/hemorrhoids-during-pregnancy/AN01720 |date=Nov 3, 2007 |publisher=MayoClinic |accessdate=2007-11-28}}</ref>
+*Internal hemorrhoids are located above the [[dentate]] line and they occur due to dilatation of the superior hemorrhoidal plexus.<ref name="pmid28567655">{{cite journal |vauthors=Guttenplan M |title=The Evaluation and Office Management of Hemorrhoids for the Gastroenterologist |journal=Curr Gastroenterol Rep |volume=19 |issue=7 |pages=30 |year=2017 |pmid=28567655 |doi=10.1007/s11894-017-0574-9 |url=}}</ref>
-[[Pregnancy]] causes hypertension and increases strain during bowel movements, and thus hemorrhoids are often associated with pregnancy.
+*The connective tissue over the superior hemorrhoidal plexus is innervated via visceral nerves and thus it is pain insensitive.
-Excessive consumption of [[alcohol]] or [[caffeine]] can both cause hemorrhoids.<ref name="titleHemorrhoids">{{cite web |author=Burney RE |title=Hemorrhoids |url=http://www.med.umich.edu/1libr/aha/aha_hem_crs.htm |date=November 2005 |publisher=University of Michigan Health System |accessdate=2007-11-28}}</ref> Both can cause [[diarrhea]]. Alcohol can also cause [[alcoholic liver disease]] leading to [[portal hypertension]]. Caffeine on the other hand can cause general [[hypertension]].
+*External hemorrhoids are located below the dentate line and occur due to dilatation of the inferior hemorrhoidal plexus.<ref>{{cite web |title=Causes of Hemorrhoids |url=http://www.mayoclinic.com/health/hemorrhoids/DS00096/DSECTION=3 |date=Nov 28, 2006  |publisher=Mayo Clinic |accessdate=2007-12-07}}</ref>
-{{#ev:youtube|QKndv13bXHA}}
+*The first step in the pathogenesis of either type of [[hemorrhoids]] is weakening of the surrounding connective tissue and vein wall. All the risk factors (old age, [[pregnancy]], [[portal hypertension]], etc) lead to aggravating this weakness or add more pressure from within the vein. <ref name="pmid17074235">{{cite journal |vauthors=Huang YT |title=[Consideration on the pathogenesis of hemorrhoids] |language=Chinese |journal=Zhonghua Wai Ke Za Zhi |volume=44 |issue=15 |pages=1019–21 |year=2006 |pmid=17074235 |doi= |url=}}</ref><ref name="pmid3265119">{{cite journal |vauthors=Le Quellec A, Bories P, Rochon JC, Garrigues JM, Poirier JL, Michel H |title=[Portal hypertension and hemorrhoids. Cause effect relationship?] |language=French |journal=Gastroenterol. Clin. Biol. |volume=12 |issue=8-9 |pages=646–8 |year=1988 |pmid=3265119 |doi= |url=}}</ref>
-===Food===
-Dehydration can cause a hard stool or chronic constipation which can lead to hemorrhoidal irritation.
-An excess of [[lactic acid]] in the stool, a product of excessive consumption of dairy products such as cheese, can cause irritation and a reduction of consumption can bring relief.  [[Vitamin E]] deficiency is also a common cause.
-Food considered "probiotic", such as yogurt with active culture, may help keep the gut functioning normally and thus help prevent flare-ups, as will the consumption of fruit.
+*Increased tone of the [[internal anal sphincter]] causing the feces to press the hemorrhoid against the muscle and thus decreasing [[venous return]] and aggravating the symptoms.<ref name="titleHemorrhoids">{{cite web |author=Burney RE |title=Hemorrhoids |url=http://www.med.umich.edu/1libr/aha/aha_hem_crs.htm |date=November 2005 |publisher=University of Michigan Health System |accessdate=2007-11-28}}</ref>
-=== Use of unnatural "sitting" toilets ===
+*The [[Circulatory anastomosis|arteriovenous]] anastomosis may play a role in the development of hemorrhoids. This is supported by the fact that some hemorrhoids improve after ligating the connecting arteries.<ref name="titleHemorrhoids during [[pregnancy]]: Treatment options - MayoClinic.com">{{cite web |author=Harms R |title=Hemorrhoids during pregnancy: Treatment options |url=http://www.mayoclinic.com/health/hemorrhoids-during-pregnancy/AN01720 |date=Nov 3, 2007 |publisher=MayoClinic |accessdate=2007-11-28}}</ref>
-Based on their very low incidence in the developing world, where people squat for bodily functions, hemorrhoids have been attributed to the use of the unnatural "sitting" toilet.<ref>{{cite journal |author=Sikirov BA |title=Primary constipation: an underlying mechanism |journal=Med. Hypotheses |volume=28 |issue=2 |pages=71–3 |year=1989 |pmid=2927355 |doi=}}</ref><ref>{{cite journal |author=Sikirov D |title=Comparison of straining during defecation in three positions: results and implications for human health |journal=Dig. Dis. Sci. |volume=48 |issue=7 |pages=1201–5 |year=2003 |pmid=12870773 |doi=}}</ref> In 1987, an Israeli physician, Dr. Berko Sikirov, published a study testing this hypothesis by having hemorrhoid sufferers convert to [[squat toilets]].<ref name="pmid3623887">{{cite journal |author=Sikirov BA |title=Management of hemorrhoids: a new approach |journal=Isr. J. Med. Sci. |volume=23 |issue=4 |pages=284–6 |year=1987 |pmid=3623887 |doi=}}</ref> Eighteen of the 20 patients were completely relieved of their symptoms (pain and bleeding) with no recurrence, even 30 months after completion of the study.  [http://naturesplatform.com/images/Sikirov_table.gif This chart] summarizes the results.
+*The redundant bulging [[mucosa]] is easily injured causing bleeding. The blood is usually bright red reflecting high oxygen content due to the proximity of [[AVA|AV anastomosis]].
-No follow-up studies have ever been published. The [http://www.fascrs.org/displaycommon.cfm?an=1&subarticlenbr=12 American Society of Colon & Rectal Surgeons] is silent regarding the therapeutic value of squatting.
+{{#ev:youtube|QKndv13bXHA}}
 ==Gross pathology==
+* External hemorrhoids appear on inspection of the [[anal verge]] as [[skin tags]] or strangulated or free prolapsed veins.
-External hemorrhoids appear on inspection of the anal verge as skin tags or prolapsed veins either strangulated or free. Internal hemorrhoids appear as bluish bulging of the veins in the mucosa.
+* Internal hemorrhoids appear as bluish bulgings of the [[veins]] in the [[mucosa]].
 {| class="wikitable"
 ![[Image:By Dr. Joachim Guntau - www.Endoskopiebilder.de, CC BY-SA 3.0, httpscommons.wikimedia.orgwindex.phpcurid=18660152.JPG|center|300px|thumb|By Dr. Joachim Guntau - www.Endoskopiebilder.de, CC BY-SA 3.0, httpscommons.wikimedia.orgwindex.phpcurid=18660152]]
@@ Line 38: / Line 35: @@
 |[[Image:Hemorrhoids - By Internet Archive Book Images - httpswww.flickr.comphotosinternetarchivebookimages14784684835Source book page httpsarchive.orgstreamdiseasesofrectum00gantdiseasesofrectum00gant-pagen490mode1up, No restrictions, ht.jpg|center|300px|thumb|By Internet Archive Book Images - httpswww.flickr.comphotosinternetarchivebookimages14784684835Source book page httpsarchive.orgstreamdiseasesofrectum00gantdiseasesofrectum00gant-pagen490mode1up, No restrictions, ht]]
 |}
 ==References==
 {{Reflist|2}}
+{{WH}}
+{{WS}}
 [[Category:Gastroenterology]]
 [[Category:Surgery]]
-[[Category:Primary care]]
 [[Category:Needs overview]]
-{{WH}}
-{{WS}}