Causes

Acute liver failure occurs when liver cells are damaged significantly and are no longer able to function. Potential causes include:

• Acetaminophen overdose. Taking too much acetaminophen (Tylenol, others) is the most common cause of acute liver failure in the United States. Outside of the United States, acetaminophen is known as paracetamol. Acute liver failure can occur after one very large dose of acetaminophen, or after higher than recommended doses every day for several days.

  If you or someone you know has taken an overdose of acetaminophen, seek medical attention as quickly as possible. Treatment may prevent liver failure. Don't wait for the signs of liver failure.

• Prescription medications. Some prescription medications, including antibiotics, nonsteroidal anti-inflammatory drugs and anticonvulsants, can cause acute liver failure.
• Herbal supplements. Herbal drugs and supplements, including kava, ephedra, skullcap and pennyroyal, have been linked to acute liver failure.
• Hepatitis and other viruses. Hepatitis A, hepatitis B and hepatitis E can cause acute liver failure. Other viruses that can cause acute liver failure include Epstein-Barr virus, cytomegalovirus and herpes simplex virus.
• Toxins. Toxins that can cause acute liver failure include the poisonous wild mushroom Amanita phalloides, which is sometimes mistaken for one that is safe to eat. Carbon tetrachloride is another toxin that can cause acute liver failure. It is an industrial chemical found in refrigerants and solvents for waxes, varnishes and other materials.
• Autoimmune disease. Liver failure can be caused by autoimmune hepatitis — a disease in which your immune system attacks liver cells, causing inflammation and injury.
• Diseases of the veins in the liver. Vascular diseases, such as Budd-Chiari syndrome, can cause blockages in the veins of the liver and lead to acute liver failure.
• Metabolic disease. Rare metabolic diseases, such as Wilson's disease and acute fatty liver of pregnancy, infrequently cause acute liver failure.
• Cancer. Cancer that either begins in or spreads to your liver can cause your liver to fail.
• Shock. Overwhelming infection (sepsis) and shock can severely impair blood flow to the liver, causing liver failure.
• Heat stroke. Extreme physical activity in a hot environment can trigger acute liver failure.

Some cases of acute liver failure have no apparent cause.