Editing Primary sclerosing cholangitis (section)

==Pathophysiology==
PSC is characterized by inflammation of the bile ducts (cholangitis) with consequent stricturing (i.e., narrowing) and hardening ([[sclerosis (medicine)|sclerosis]]) of these ducts due to scar formation, be it inside and/or outside the liver.<ref name=":0">{{cite journal | vauthors = Hirschfield GM, Karlsen TH, Lindor KD, Adams DH | title = Primary sclerosing cholangitis | journal = Lancet | volume = 382 | issue = 9904 | pages = 1587–1599 | date = November 2013 | pmid = 23810223 | doi = 10.1016/s0140-6736(13)60096-3 | s2cid = 13423425 }}</ref>  The resulting scarring of the bile ducts obstructs the flow of bile, which further perpetuates bile duct and liver injury.  Chronic impairment of bile flow due to blockage and dysfunctional bile transport ([[cholestasis]]) causes progressive biliary fibrosis and ultimately biliary cirrhosis and liver failure.<ref name=Robbins>{{cite book  | vauthors = Robbins SL, Kumar V, Cotran RS  | title = Robbins basic pathology  | publisher = Saunders  | location = Philadelphia  | year = 2003  | pages = [https://archive.org/details/robbinsbasicpath0000unse/page/620 620–1]  | edition = 7th  | chapter = Chapter 16  | isbn = 978-0-7216-9274-6  | chapter-url-access = registration  | chapter-url = https://archive.org/details/robbinsbasicpath0000unse/page/620 }}</ref>

The primary physiological function of bile is to assist in the breakdown and absorption of fat in the intestinal tract; a relative deficiency of bile can lead to fat malabsorption and deficiencies of [[fat-soluble vitamins]] (A, D, E, K).<ref>{{cite journal |last1=Iravani |first1=Shahrokh |last2=Dooghaie-Moghadam |first2=Arash |last3=Razavi-Khorasani |first3=Niloofar |last4=Moazzami |first4=Bobak |last5=Dowlati Beirami |first5=Amirreza |last6=Mansour-Ghanaei |first6=Alireza |last7=Majidzadeh-A |first7=Keivan |last8=Mehrvar |first8=Azim |last9=Khoshdel |first9=Alireza |last10=Nasiri Toosi |first10=Mohssen |last11=Sadeghi |first11=Amir |title=An update on treatment options for primary sclerosing cholangitis |journal=Gastroenterology and Hepatology from Bed to Bench |date=2020 |volume=13 |issue=2 |pages=115–124 |pmid=32308932 |pmc=7149806 }}</ref>

Liver enlargement is seen due to portal hypertension caused by compression of [[portal vein]]s by the proximate sclerosed intrahepatic bile ducts, and leads to right upper quadrant abdominal pain.{{cn|date=March 2022}}