Viral Hepatitis: This is a common cause of sudden elevation in both total and direct bilirubin due to the liver's inflammation and impaired ability to process bilirubin. The sudden onset and the pattern of bilirubin elevation are consistent with acute liver injury.

Drug-Induced Hepatotoxicity: Certain medications can cause liver damage, leading to a sudden increase in bilirubin levels. The mechanism can vary, including direct toxicity to liver cells or an allergic reaction.
Alcoholic Hepatitis: In individuals who consume alcohol heavily, a sudden increase in bilirubin can occur due to liver inflammation and damage.
Biliary Obstruction: Blockage of the bile ducts, which can be due to gallstones, tumors, or other causes, leads to a buildup of direct bilirubin in the blood.

Septic Shock or Sepsis: Although less common, severe infections can lead to liver dysfunction and a sudden rise in bilirubin levels. Missing this diagnosis can be fatal.
Hemolytic Crisis: Conditions like autoimmune hemolytic anemia can lead to a rapid breakdown of red blood cells, causing an increase in indirect bilirubin, but in severe cases, it can also affect liver function and lead to an increase in direct bilirubin.
Ischemic Hepatitis (Shock Liver): Reduced blood flow to the liver, as seen in shock or severe heart failure, can cause liver injury and a sudden rise in bilirubin levels.

Wilson's Disease: A genetic disorder that leads to copper accumulation in the liver, causing liver damage and potentially a sudden increase in bilirubin levels, especially in young individuals.
Budd-Chiari Syndrome: A rare condition caused by obstruction of the hepatic veins, leading to liver congestion, damage, and elevated bilirubin levels.
Primary Biliary Cholangitis (PBC): An autoimmune disease of the liver that can cause progressive destruction of the bile ducts within the liver, leading to a buildup of direct bilirubin, although the onset is usually more gradual.