Pancreatic Cancer: This is often considered the most likely diagnosis for painless jaundice, especially in older adults, due to its high prevalence and the fact that it can cause obstructive jaundice without significant pain in its early stages.

Cholangiocarcinoma: A cancer of the bile duct, which can also present with painless jaundice due to obstruction of the bile ducts.
Gallstones: While gallstones often cause painful jaundice, some cases can be painless, especially if the stone is lodged in the common bile duct without causing significant obstruction or inflammation.
Primary Sclerosing Cholangitis (PSC): A chronic liver disease that leads to scarring and narrowing of the bile ducts, which can cause jaundice. It might be painless, especially in its early stages.

Hepatocellular Carcinoma: Although less common than pancreatic cancer, hepatocellular carcinoma can cause obstructive jaundice and is critical to diagnose early due to its poor prognosis if left untreated.
Ampullary Cancer: A rare tumor at the junction of the bile and pancreatic ducts, which can cause painless jaundice due to obstruction.
Bile Duct Stricture: This could be due to various causes, including iatrogenic (post-surgical), traumatic, or infectious, and can lead to obstructive jaundice.

Carol's Disease: A rare congenital disorder of the intrahepatic bile ducts that can cause recurrent cholangitis and potentially painless jaundice.
Mirizzi Syndrome: A rare condition where a gallstone becomes impacted in the cystic duct and causes obstruction of the common bile duct, potentially leading to painless jaundice.
Parasitic Infestations: Certain parasites, like Clonorchis sinensis, can infect the bile ducts and cause obstructive jaundice, though this is more common in specific geographic regions.