What Does the Liver Do? Understanding Its Key Functions

The liver — often referred to as the hepatic organ — is one of the most vital and versatile organs in the human body. Tucked beneath your right rib cage, it is the body's largest internal organ. Spongy and about the size of a football, the liver performs life-sustaining liver functions that the body needs to thrive.^1,2

Anatomy of the liver

The average size of the liver depends on a person's height and weight. Typically, it weighs about 3 pounds in an adult.^1-3

The liver has 2 main sections, also called lobes: the larger right lobe and the smaller left lobe. These lobes are further divided into smaller segments. Each has its own blood supply.^1-3

The liver receives blood from 2 vital sources: the hepatic artery and the hepatic portal vein. These carry blood to the liver. Without this blood flow, the liver could not carry out its many essential hepatic functions.^1-3

The liver's functions (hepatic functions)

The liver performs over 500 essential functions that keep your body running smoothly. Here are just a few.^1-3

Filters blood

The liver filters blood all day, every day — about 1 liter of blood every single minute. That is why it is a deep, reddish-brown color.^1-3

During this filtration process, the liver breaks down harmful substances such as alcohol, drugs, and toxins. Then it expels them as waste. It acts as the body's primary detoxification system. Filtering the blood is one of the liver's most important functions.^1-3

Metabolizes carbs, proteins, and fats

The liver helps turn what we eat and drink — carbohydrates, fats, and proteins — into energy. It converts extra sugar (glucose) into glycogen and stores it for later use. The liver also manages cholesterol levels and processes amino acids, which are the building blocks of proteins.^1,2

Produces bile

Bile is an acidic substance that helps digest fats and break down food. Bile is created in the liver, stored in the gallbladder — tucked just under the liver — and released into the small intestine as needed.^1,2

Stores nutrients

The liver stores essential nutrients, including vitamins, minerals, and iron. It also stores glycogen that the body can use quickly for energy when needed.^1-3

Regulates blood clotting

The liver produces proteins that are essential for blood clotting. Blood needs to clot if an injury occurs. This clotting process helps prevent excessive bleeding.^1-3

Boosts the immune system

The liver helps fight off infections by producing substances that support the immune system and removing bacteria from the blood.^1,3

How the liver's hepatic functions keep you healthy

The liver's ability to detoxify the body is crucial. It breaks down medicines, drugs, and poisonous substances and prepares them for release from the body. Once the liver has filtered the blood, these by-products are further filtered by the kidneys into urine. The liver also converts ammonia, which is produced during protein metabolism, into urea. Urea is then excreted by the kidneys.^1-3

When it comes to metabolism, the liver maintains blood sugar levels by storing and releasing glucose as needed. For example, during fasting or intense exercise, the liver converts stored glycogen back into glucose so the body can use it for energy.^1-3

Producing and secreting bile is another necessary liver function that helps us survive. Bile helps break down fats in the digestive tract. This makes them easier to digest and absorb. Bile also helps absorb fat-soluble vitamins, providing the body with the nutrients it needs to survive. Bile by-products are then released from the body through stool.^1-3

Liver conditions and hepatocellular health

The liver is very resilient. It can take a lot of wear and tear and still function. But too much damage for too long can lead to fat buildup, inflammation, and scarring in the liver. This scarring interferes with the organ's ability to perform its normal liver functions.^1,2

When the liver is not working properly, a whole slew of health complications can arise, such as:^1,2

• Hepatitis — Inflammation in the liver can result from viral hepatitis infections, autoimmune reactions, and other causes.
• Fatty liver disease — Buildup of fat in the liver can cause inflammation and damage at the hepatocellular level. This fat buildup is often linked to obesity and type 2 diabetes.
• Fibrosis — This means scarring of the liver. With fibrosis, there is typically time to reverse the damage through treatment and lifestyle changes.
• Cirrhosis — With cirrhosis, there is permanent scarring of the liver. Blood flow to the liver is completely blocked. Cirrhosis is serious and can lead to liver failure.
• Liver cancer — Cancer cells can grow in the liver as a result of inflammation and liver damage. Liver cancer is also known as hepatocellular carcinoma, named for the hepatocellular tissue where it originates.
• Liver failure — The liver is no longer functioning. A liver transplant from a deceased or living donor is needed in order to survive.

Keeping your liver (and hepatic system) healthy

The liver is truly an extraordinary organ. We all need a healthy liver — and healthy liver functions — in order to live.¹

Keeping your liver healthy involves eating a balanced diet, getting regular exercise, consuming moderate to no alcohol, and avoiding illicit drugs. Getting vaccinated for hepatitis A and B can help prevent viral infections. Stay on top of regular health checkups to monitor your liver health, especially if you have comorbidities like obesity or type 2 diabetes.²