What Does the Liver Do?

Medically Reviewed By William C. Lloyd III, MD, FACS
doctor pointing at liver

Your liver is the largest and among the hardest working internal organs in your body. It plays an essential role in your health, which means you can’t live without it. A normal healthy adult liver weighs around 3.5 pounds and is about the size of a football. It is located in the right side of your abdomen, just below your ribs. Learn more about what your liver does, symptoms of liver disease, and how you can reduce your risk of developing liver-related problems.

Your Liver Has Many Functions

Your liver performs 500 distinct functions while you go about your day. Arguably, the most important function is how it helps cleanse your body of toxins and unnecessary byproducts of everything you eat or drink, including many medications. A healthy liver controls the amount of minerals and vitamins in the blood and filters out toxins, metabolic waste products, and poisons. The liver also produces bile necessary for digestion, especially fats and some vitamins.

Other liver functions include:

  • Breaking down fats
  • Producing blood for the fetus in pregnant women
  • Storing iron
  • Breaking down old or damaged blood cells
  • Storing glycogen, which helps your body use carbohydrates
  • Breaking down medications so the active ingredient is released
  • Regulating blood clotting times
  • And much more


Hepatitis is a disease with multiple subtypes: A, B and C are most common. All are viral infections and the distinction is based on the type of virus. The most common one is hepatitis C, which affects over 2 million people in the United States. Experts believe there are about 850,000 people in the U.S. with hepatitis B, and on any day almost 7,000 cases of active hepatitis A.

Hepatitis A is an acute, short-term illness, usually spread through contaminated food or drink, especially in places that don’t have adequate sanitization. Most people who contract hepatitis A do fully recover, but the disease can cause permanent liver damage. There is a vaccine; experts recommend that all infants be vaccinated, as well as anyone traveling abroad where sanitation may be questionable and those who may be at risk of coming in contact with the virus.

Hepatitis B is spread when people come in contact with the body fluids of someone who has the disease. The contact doesn’t have to be direct. For example, it can occur if someone with hepatitis B shares a personal item, like a razor or a toothbrush with someone who is not infected. Up to a quarter of people with hepatitis B who are chronically infected go on to develop chronic liver disease or liver cancer. There is also a vaccine for hepatitis B, often given together with the one for hepatitis A. This vaccine is recommended for: infants; anyone who is in a relationship with someone who is infected; people with multiple sexual partners; people who work in healthcare facilities, prisons, or public safety environments; and people who have chronic liver disease.

Hepatitis C is transmitted the same way as hepatitis B. Hepatitis C is considered to be more serious because there is no vaccine and most, up to 85% of those infected with the virus go on to develop chronic infection. Up to 20% of those who develop chronic infection, develop cirrhosis of the liver. There is treatment for hepatitis C, either an 8- or 12-week program, depending on the medication.

A fourth type of hepatitis is autoimmune hepatitis. In autoimmune hepatitis, the immune system attacks the liver, causing inflammation. This chronic condition can go into remission, but relapses are common.

Other Liver Problems

Four other types of liver problems include: fatty liver disease, primary hemochromatosis, cirrhosis of the liver, and liver cancer.

There are two types of fatty liver disease: alcoholic fatty liver disease and non-alcoholic fatty liver disease. Alcoholic fatty liver disease, also called alcoholic steatohepatitis, is caused by excessive alcohol consumption. It can cause inflammation and damage to liver cells. Non-alcoholic fatty liver disease is caused by too much fat in the liver, which can cause scarring. With too much scar tissue, the liver is less able to filter toxins and perform other functions. Non-alcoholic fatty liver disease affects about 25% of the adult population in the U.S., making it the most common liver disease in the country. It can run in your family (genetic) or be caused by certain medications or a diet that includes a lot of fructose sugar.

Primary hemochromatosis is a genetic disorder where the body absorbs too much iron from food. This condition affects about one out of every 3 non-Hispanic whites in the U.S. Too much iron in your blood can cause damage to your liver. Secondary hemochromatosis is caused by another disease or condition, such as anemia or liver disease.

Cirrhosis of the liver is caused by scars on the liver tissue. Scar tissue replaces healthy liver tissue to the point where the liver cannot function as it should. Cirrhosis can be caused by consuming too much alcohol, too much medication that is metabolized in the liver, non-alcoholic fatty liver disease, hepatitis B and hepatitis C. It can also be inherited or the result of other diseases, such as chronic heart failure.

Liver cancer incidence rates continue to rise in the United States. The number of people diagnosed each year has tripled since 1980, with over 42,000 adults diagnosed in 2019. Because there are few distinct early stage symptoms, liver cancer is usually diagnosed in advanced stages. Although anyone can develop liver cancer, those at highest risk are people who have hepatitis B or hepatitis C, cirrhosis, hemochromatosis, or diabetes. People who excessively drink alcohol or who are obese are also at risk.

Taking Care of Your Liver

Because it is essential to life, your liver can regenerate more liver cells if it’s not badly damaged. Liver cleansing products or programs are widely marketed. Keep in mind, your liver doesn’t need to be cleansed as it does so naturally. The most important thing to take care of your liver is to limit consumption of any products that tax the liver, such as alcohol, nonsteroidal anti-inflammatories (NSAIDs), and illicit drugs. If you use needles for injections, never share them with someone else and always use a clean needle. Eating a healthy diet, exercising, and getting vaccinated against hepatitis A and hepatitis B are also important.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Mar 30
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