The liver is the second largest organ in your body. It performs several different functions.

Your liver processes everything you eat and drink, producing energy and nutrients for your body to use. It filters out harmful substances from your blood — such as alcohol — and helps your body fight off infection.

Exposure to viruses or harmful chemicals can damage your liver. When your liver is damaged, you may develop liver failure, also known as hepatic failure. In those with liver damage, the liver may eventually stop functioning correctly.

Liver failure is a serious condition. If you develop liver failure, you should receive treatment immediately.

Liver failure can be either acute or chronic.

Acute liver failure

Acute liver failure strikes fast. You can experience loss of liver function within weeks or even days. It may happen suddenly without showing any symptoms.

Common causes of acute liver failure include poisoning from mushrooms or drug overdose, which can occur from taking too much acetaminophen (Tylenol).

Chronic liver failure

Chronic liver failure develops more slowly than acute liver failure. It can take months or even years before you exhibit any symptoms.

Chronic liver failure is often the result of cirrhosis, which occurs when healthy liver tissue is replaced with scar tissue. According to research from 2021, cirrhosis is most often caused by hepatitis C infection, alcohol overuse, or nonalcoholic fatty liver disease (NAFLD).

During chronic liver failure, your liver becomes inflamed. This inflammation causes the formation of scar tissue over time. As your body replaces healthy tissue with scar tissue, your liver gradually loses its typical range of function.

A variety of causes are associated with liver failure.

Causes associated with acute liver failure

Acute liver failure, also known as fulminant hepatic failure, can occur even if you don’t have a preexisting liver disease.

The most common cause of acute liver failure in the United States is acetaminophen (Tylenol) overdose.

Acetaminophen is an over-the-counter (OTC) drug. Always follow the recommended dosage on the label. If you think you may have overdosed, contact a healthcare professional immediately.

Acute liver failure may also be caused by:

Acute liver failure can be genetic, passed along by genes you inherited from one or both of your parents. If you have a genetic liver disease, you’re more susceptible to liver failure.

Causes associated with chronic liver failure

Chronic liver failure is the result of long-term inflammation that leads to scarring of healthy liver tissues (fibrosis). The American Liver Foundation (ALF) explains that when scar tissue takes over the majority of healthy liver tissues, it becomes known as cirrhosis.

A 2021 overview of hepatic cirrhosis notes that, while some of the triggers of hepatic inflammation are linked to underlying health conditions, others can be more difficult to identify. These may include the following:

Hepatitis C infection

If you have hepatitis C, you have a higher risk of developing chronic liver failure or cirrhosis.

This virus often goes undetected, as symptoms are not common. Emory Healthcare reports that, in some cases, people experience significant liver damage before knowing they have a hepatitis C infection.

According to the Centers for Disease Control and Prevention (CDC), 5 to 25 percent of people in the United States with chronic hepatitis C develop cirrhosis within 10 to 20 years. The ALF notes that it’s the most common cause of cirrhosis in the country.

The hepatitis C virus is spread through the blood. If the blood from a person with the infection enters your body, you can catch it. Needle sharing and using unsanitized needles for tattoos or piercings can spread hepatitis C.

Alcohol overuse

Another common cause of cirrhosis and subsequent chronic liver failure is harmful use of alcohol.

According to Emory Healthcare, this is usually the result of at least a decade of heavy drinking. The ALF estimates that 10 to 20 percent of people who engage in alcohol overuse will develop cirrhosis.

Usually, your liver breaks down any alcohol that you consume. But if you drink too much, your liver can’t break down the alcohol fast enough. Toxic chemicals in alcohol can trigger inflammation in your liver and cause your liver to swell. Over time, this damage can lead to cirrhosis.

Nonalcoholic fatty liver disease

It’s natural for your liver to contain a small amount of fat. However, the ALF notes if the weight of your liver is made up of more than 5 to 10 percent of fat, it is called steatosis, or fatty liver. This may eventually lead to NAFLD.

NAFLD is a type of liver disease that is not caused by alcohol overuse or misuse. Instead, according to the U.S. Department of Health and Human Services, NAFLD is associated with:

While early stages of NAFLD may not cause harm, it may lead to more liver inflammation and scarring. The National Health Service notes that cirrhosis and liver failure caused by NAFLD develops after many years of severe inflammation.

Less common causes

From this 2021 overview, other possible but less common causes of chronic liver failure may include:

Unknown causes

It’s also possible to develop liver failure without an identifiable cause.

Symptoms of liver failure may include:

These symptoms can also be attributed to other conditions or disorders, which can make liver failure hard to diagnose. Some people don’t show any symptoms until their liver failure has progressed to a fatal stage. You may be disoriented, drowsy, or even slip into a coma by the time you reach this stage.

If you have liver dysfunction, you may develop jaundice. Toxins can build up in your brain and cause sleeplessness, lack of concentration, and even decreased mental function.

You may also experience an enlarged spleen, stomach bleeding, and kidney failure. Liver cancer can also develop.

If you’re experiencing symptoms, seek help from your doctor. Be sure to let them know if you have a history of alcohol misuse, genetic irregularities, or other medical conditions.

There are several blood screening tests that can be done to detect any abnormalities in the blood, including abnormalities that may imply liver failure.

If you experience drug poisoning, such as from acetaminophen, your doctor may prescribe medication to reverse the effects. Your doctor may also prescribe medication to stop any internal bleeding.

A biopsy is a common test used to determine liver damage. During a liver biopsy, your doctor extracts a small piece of your liver to be examined in a lab.

Some liver damage can be reversed if it’s caught early. The damaged liver may repair itself. Medication can also help the repair process.

You’re at higher risk of fatty liver disease if you have overweight or if you have a diet that’s high in fat. Making a lifestyle change to a healthier diet may help. If you have liver damage and drink alcohol, removing alcohol from your diet is also important.

Learn more about the fatty liver diet.

Treatment depends on the stage of the disease.

Your doctor may prescribe medications. If only part of your liver is damaged, surgery may be recommended to remove the damaged part. A doctor can also order imaging tests of your liver, such as a CT scan or an MRI, to look for damage.

If a healthy liver is damaged, it can grow back.

If the damage is too severe, which can sometimes be the case with fast-acting acute liver failure, a liver transplant may be necessary.

The most common causes of liver failure may be prevented by addressing the underlying causes. Talk with your doctor about taking steps to help mitigate the hepatic effects of the following:

  • Hepatitis C. You can take steps to prevent this infection such as practicing safe sex and avoiding sharing needles and tattoo equipment. If you are diagnosed with hepatitis C, work with your doctor to treat this infection to prevent further damage to your liver. The ALF has resources for recognizing, testing, and diagnosing hepatitis C.
  • Alcohol overuse. While moderate alcohol consumption is unlikely to lead to liver failure, your doctor may recommend you avoid alcohol entirely if you have liver disease. If you’re given the go-ahead to consume alcohol moderately, keep healthy guidelines in mind. The Dietary Guidelines for Americans define moderate drinking as up to one drink per day for women and up to two drinks per day for men.
  • NAFLD. According to the NHS, preventing NAFLD may look like treatment for risk factors, such as obesity, diabetes, high blood pressure, and high cholesterol. Additionally, your doctor may recommend that you lose weight, exercise regularly, and/or make dietary changes.
  • Medications, supplements, and herbs. Only take these as prescribed, and avoid taking any over-the-counter medications and “natural” remedies without asking your doctor first. This may help reduce your risk of acute liver failure.

You should see your doctor if you have any potential signs of liver failure. This can include symptoms like jaundice, stool changes, and unintentional weight loss.

You may not have liver failure, but if you do, early detection is important. Liver failure can be a silent killer because you may not experience symptoms until it’s too late. With the proper treatment, you can control liver disease and lead a healthy life.