Gallstones: The most common cause of regional jaundice, particularly in women, due to the obstruction of the common bile duct. This condition leads to a buildup of bilirubin in the blood, causing jaundice.

Cholangitis: An infection of the bile duct, which can cause jaundice due to obstruction and inflammation. It often presents with fever, abdominal pain, and jaundice.
Pancreatic Cancer: A malignancy that can obstruct the bile duct where it passes through or near the pancreas, leading to jaundice. Weight loss, abdominal pain, and jaundice are common symptoms.
Ampullary Cancer: A rare tumor that occurs at the ampulla of Vater, where the bile and pancreatic ducts empty into the small intestine. It can cause obstructive jaundice.

Hemolytic Anemia: Conditions like autoimmune hemolytic anemia can cause jaundice due to the breakdown of red blood cells. Although less common as a cause of regional jaundice, missing this diagnosis can lead to severe anemia.
Budd-Chiari Syndrome: A rare condition caused by thrombosis of the hepatic veins, leading to liver dysfunction and jaundice. It's crucial not to miss this diagnosis due to its potential for severe complications.
Sclerosing Cholangitis: A chronic liver disease characterized by inflammation and scarring of the bile ducts inside and outside the liver. It can lead to jaundice and has significant implications for liver function.

Caroli's Disease: A rare congenital disorder of the bile ducts, characterized by dilatation of the intrahepatic bile ducts. It can lead to recurrent cholangitis and jaundice.
Mirizzi Syndrome: A rare condition where a gallstone becomes impacted in the cystic duct, causing obstruction of the common bile duct and leading to jaundice.
Bile Duct Cysts (Choledochal Cysts): Congenital anomalies of the bile duct that can cause obstructive jaundice due to their potential to obstruct the bile ducts.