Acute liver failure

Acute liver failure is loss of liver function that happens quickly — in days or weeks — usually in a person who has no preexisting liver disease. It's most often caused by a hepatitis virus or drugs, such as acetaminophen. Acute liver failure is less common than chronic liver failure, which develops more slowly.

Acute liver failure, also known as fulminant hepatic failure, can cause serious complications, including bleeding and increased pressure in the brain. It's a medical emergency that requires hospitalization.

Depending on the cause, acute liver failure can sometimes be reversed with treatment. In many situations, though, a liver transplant may be the only cure.

Symptoms of acute liver failure may include:

• Yellowing of the skin and eyeballs, called jaundice.
• Pain in the upper right belly area, called the abdomen.
• A swollen belly, known as ascites.
• Nausea and vomiting.
• A general sense of feeling unwell, known as malaise.
• Disorientation or confusion.
• Sleepiness.
• Breath with a musty or sweet odor.
• Tremors.

Acute liver failure occurs when liver cells are seriously damaged and are no longer able to function. Possible 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 happen 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 symptoms of liver failure.

• Hepatitis and other viruses. Hepatitis A, hepatitis B and hepatitis E increase the risk of acute liver failure. Other viruses that can increase risk include Epstein-Barr virus, cytomegalovirus and herpes simplex virus.
• Prescription medicines. Some prescription medicines, 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.
• 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 the 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, sometimes cause acute liver failure.
• Cancer. Cancer that either begins in or spreads to the liver can cause the liver to fail.
• Shock. Overwhelming infection, called sepsis, and shock can severely reduce 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 obvious cause.

Risk factors for acute liver failure include:

• Being female. A majority of people affected by acute liver failure are female.
• Underlying illness. Many conditions, including viral hepatitis, metabolic disease, autoimmune disease and cancer can increase the risk of acute liver failure.

Acute liver failure often causes complications, including:

• Too much fluid in the brain, called cerebral edema. Too much fluid causes pressure to build up in the brain, which can lead to disorientation, severe mental confusion and seizures.
• Bleeding and bleeding disorders. A failing liver cannot make enough clotting factors, which help blood to clot. Bleeding in the gastrointestinal tract is common with this condition. It may be difficult to control.
• Infections. People with acute liver failure are more likely to develop infections, particularly in the blood and in the respiratory and urinary tracts.
• Kidney failure. Kidney failure often occurs after liver failure, especially with an acetaminophen overdose, which damages both the liver and the kidneys.

Reduce your risk of acute liver failure by taking care of your liver.

• Follow instructions on medicines. If you take acetaminophen or other medicines, check the package insert for the recommended dose, and don't take more than that. If you already have liver disease, ask your healthcare team if it is safe to take any amount of acetaminophen.
• Tell your healthcare team about all your medicines. Even nonprescription and herbal medicines can interact with prescription drugs you're taking.
• Drink alcohol in moderation, if at all. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
• Avoid risky behavior. Get help if you use illicit intravenous drugs. Don't share needles. Use condoms during sex. If you get tattoos or body piercings, make sure the shop you choose is clean and safe. Don't smoke.
• Get vaccinated. If you have chronic liver disease, a history of any type of hepatitis infection or an increased risk of hepatitis, talk to your care team about getting the hepatitis B vaccine. A vaccine also is available for hepatitis A.
• Be careful not to come into contact with other people's blood and body fluids. Accidental needle sticks or improper cleanup of blood or body fluids can spread hepatitis viruses. Sharing razor blades or toothbrushes also can spread infection.
• Don't eat wild mushrooms. It can be difficult to tell the difference between a poisonous mushroom and one that is safe to eat.
• Take care with aerosol sprays. When you use an aerosol cleaner, make sure the room is ventilated, or wear a mask. Take similar protective measures when spraying insecticides, fungicides, paint and other toxic chemicals. Follow product instructions carefully.
• Watch what gets on your skin. When using insecticides and other toxic chemicals, cover your skin with gloves, long sleeves, a hat and a mask.
• Maintain a healthy weight. Obesity can cause a condition called nonalcoholic fatty liver disease (NAFLD), now called metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD may lead to serious liver damage.