Viral Hepatitis: This is often the most common cause of hyperbilirubinemia in adults, particularly due to hepatitis A, B, and C viruses, which can cause liver inflammation leading to elevated bilirubin levels.

Alcoholic Liver Disease: Chronic alcohol consumption can lead to liver damage, including alcoholic hepatitis and cirrhosis, which can result in hyperbilirubinemia.
Drug-Induced Liver Injury: Various medications and drugs can cause liver injury, leading to elevated bilirubin levels.
Gallstones: Obstruction of the bile ducts by gallstones can cause conjugated hyperbilirubinemia.
Hemolytic Anemia: Conditions that lead to increased red blood cell destruction, such as autoimmune hemolytic anemia, can result in elevated levels of indirect (unconjugated) bilirubin.

Budd-Chiari Syndrome: A rare condition caused by thrombosis of the hepatic veins, which can lead to liver failure and is potentially life-threatening if not promptly diagnosed and treated.
Wilson's Disease: A genetic disorder that leads to copper accumulation in the liver, causing liver damage and potentially life-threatening if not recognized and managed appropriately.
Acute Liver Failure: Conditions such as acetaminophen overdose, ischemic hepatitis, or severe viral hepatitis can lead to rapid deterioration of liver function, requiring urgent medical attention.

Dubin-Johnson Syndrome: A rare genetic disorder characterized by chronic jaundice due to an inability to secrete conjugated bilirubin into the bile.
Rotor Syndrome: A benign condition similar to Dubin-Johnson syndrome but without liver discoloration, causing a mild increase in conjugated bilirubin.
Crigler-Najjar Syndrome: A rare congenital disorder affecting the enzyme responsible for converting unconjugated bilirubin to conjugated bilirubin, leading to very high levels of unconjugated bilirubin.
Primary Biliary Cholangitis (PBC): An autoimmune disease of the liver characterized by a progressive destruction of the bile ducts within the liver, leading to cholestasis and potentially cirrhosis.
Primary Sclerosing Cholangitis (PSC): A chronic liver disease characterized by inflammation and scarring of the bile ducts, which can lead to liver failure.