Editing Hemorrhoid (section)

==Causes==
The exact cause of symptomatic hemorrhoids is unknown.<ref name=CE2009 /> A number of factors are believed to play a role, including irregular bowel habits ([[constipation]] or [[diarrhea]]), lack of exercise, nutritional factors (low-fiber diets), increased intra-abdominal pressure (prolonged straining, [[ascites]], an intra-abdominal mass, or [[pregnancy]]), genetics, an absence of valves within the hemorrhoidal veins, and aging.<ref name=Review09 /><ref name=Kaidar2007 /> Other factors believed to increase risk include [[obesity]], prolonged sitting,<ref name=World09 />{{dubious|Sitting|reason=The cited paper does not contain the word "sitting"|date=February 2023}} a [[chronic condition|chronic]] [[cough]], and [[pelvic floor dysfunction]].<ref name=Beck2011 /> Squatting while defecating may also increase the risk of severe hemorrhoids.<ref>{{cite book |last1 = Bland |first1 = Kirby I. |last2 = Sarr |first2 = Michael G. |last3 = Büchler |first3 = Markus W. |last4 = Csendes |first4 = Attila |last5 = Garden |first5 = Oliver James |last6 = Wong |first6 = John |title = General Surgery: Principles and International Practice |date = 2008 |publisher = Springer Science & Business Media |isbn = 9781846288326 |page = 857 |url = https://books.google.com/books?id=0sdcAQLAc-MC&pg=PA857 |language = en |url-status = live |archive-url = https://web.archive.org/web/20170811182237/https://books.google.ca/books?id=0sdcAQLAc-MC&pg=PA857 |archive-date = 2017-08-11 }}</ref> Evidence for these associations, however, is poor.<ref name=Beck2011 /> Being a receptive partner in [[Anal sex|anal intercourse]] has been listed as a cause.<ref>{{cite book |last1=Fitzgerald |first1=Margaret A. |url=https://books.google.com/books?id=0gsIEAAAQBAJ&dq=hemorrhoids+anal+intercourse&pg=PT672 |title=Nurse Practitioner Certification Exam Prep |date=4 December 2020 |publisher=[[F.A. Davis]] |isbn=978-1-7196-4298-9 |language=en |access-date=6 July 2023}}</ref><ref>{{cite book |last1=Ferri |first1=Fred F. |url=https://books.google.com/books?id=YxWbDwAAQBAJ&dq=hemorrhoids+anal+intercourse&pg=PA648-IA2 |title=Ferri's Clinical Advisor 2020 E-Book: Ferri's Clinical Advisor 2020 E-Book |date=1 June 2019 |publisher=Elsevier Health Sciences |isbn=978-0-323-67977-0 |language=en |access-date=6 July 2023}}</ref><ref>{{cite book |last1=Bernstein |first1=Melissa |url=https://books.google.com/books?id=ICQPnhr71zwC&dq=hemorrhoids+anal+intercourse&pg=PA115 |title=Nutrition for the Older Adult |last2=Luggen |first2=Ann Schmidt |date=28 January 2011 |publisher=[[Jones & Bartlett Publishers]] |isbn=978-1-4496-6396-4 |page=116 |language=en |access-date=6 July 2023}}</ref>

During pregnancy, pressure from the [[fetus]] on the abdomen and hormonal changes cause the hemorrhoidal vessels to enlarge. The birth of the baby also leads to increased intra-abdominal pressures.<ref>{{cite web |url=http://digestive.niddk.nih.gov/ddiseases/pubs/hemorrhoids/ |title=Hemorrhoids |access-date=18 March 2010 |author=National Digestive Diseases Information Clearinghouse |date=November 2004 |work=[[National Institute of Diabetes and Digestive and Kidney Diseases]] (NIDDK), [[NIH]] |url-status=dead |archive-url=https://web.archive.org/web/20100323231446/http://digestive.niddk.nih.gov/ddiseases/pubs/hemorrhoids/ |archive-date=2010-03-23 }}</ref> Pregnant women rarely need surgical treatment, as symptoms usually resolve after delivery.<ref name=Review09 />