Your liver is your body’s largest solid organ. On average, it weighs around 3 pounds in adulthood and is roughly the size of a football. This organ is vital to the body’s metabolic, detoxification, and immune system functions. Without a functioning liver, a person cannot survive.

The liver’s position is mostly in the right upper portion of the abdomen, just below the diaphragm. A portion of the liver is located in the left upper abdomen as well. Keep reading to find out exactly what the liver does, its purpose, and some diseases that affect it.

The liver’s major functions are in the metabolic processes of the body. These include:

  • breaking down or converting certain substances
  • balancing energy metabolism by converting glycogen to glucose and storing extra glucose by converting it to glycogen
  • making toxins less harmful to the body and removing them from the bloodstream

The liver does this by receiving blood with nutrients from the digestive organs via a vein known as the hepatic portal vein.

The many cells of the liver, known as hepatocytes, accept and filter this blood. They act as little sorting centers, determining:

  • which nutrients should be processed
  • what should be stored
  • what should be eliminated via the stool
  • what should go back to the blood

The liver stores fat-soluble vitamins as well as minerals such as copper and iron, releasing them if the body needs them. It also helps to break down fats in a person’s diet. It either metabolizes fats or releases them as energy.

The liver also produces an estimated 800 to 1,000 milliliters (ml) of bile each day. This bile is transported via bile ducts that eventually join and form the common bile duct that flows into the small intestine. The small intestine uses the bile to further help with break down and absorption of fats. Extra bile is stored in the gallbladder.

The liver produces and breaks down proteins as well. The byproduct of breaking down amino acid proteins is called ammonia, which can be toxic to the body in large amounts. The liver turns the toxic ammonia into a substance called urea. The liver releases this into the blood where the kidneys excrete it via the urine. The liver also removes alcohol from the blood, as well as affects many medications a person takes.

As if these functions weren’t enough, the liver also plays major roles in the following:

  • creating immune system factors that can fight against infection
  • creating proteins responsible for blood clotting
  • breaking down old and damaged red blood cells
  • storing extra blood sugar as glycogen

When taking all this into consideration, it’s easy to see how important the liver is to a person’s health.

The liver is a half-moon shaped organ that’s fairly straight on the bottom. It’s tilted slightly in the body’s cavity, with the left portion above the stomach and the right portion above the first part of the small intestine.

The liver has two main portions, also called lobes. Each lobe is further divided into eight segments. Each segment has an estimated 1,000 lobules, also called small lobes. Each of the lobules has a small tube — a duct — that flows into other ducts that joins to become the common hepatic duct. This meets the cystic duct and then becomes the common bile duct.

Compared to the rest of the body, the liver has a significant amount of blood flowing through it — an estimated 13 percent of the body’s blood is in the liver at any given time.

The liver is truly an amazing organ in that it has the capacity to regenerate. This means that after an injury or surgery to remove tissue, the liver tissue can grow back to a certain extent.

The liver starts growing back by having the existing cells enlarge. Then, new liver cells start to multiply.

Within a week after removing two-thirds of the liver, the liver can return to the same weight it was before surgery. The liver has been known to regenerate completely after as many as 12 partial liver removal surgeries.

Unfortunately, there are many diseases that can affect the liver and its functioning. Examples of common conditions that affect the liver include:

Autoimmune hepatitis

This condition occurs when the body’s immune system attacks itself and destroys healthy liver tissue. Autoimmune hepatitis can lead to cirrhosis and other liver damage.

Biliary atresia

Biliary atresia is a condition that adversely affects a person’s bile ducts and bile flow from when they’re an infant. If left untreated, the condition can cause liver scarring and affect liver tissue.

Cirrhosis

Cirrhosis is a condition where scar tissue replaces healthy liver tissue. A number of conditions can cause cirrhosis. They include long-term excessive alcohol use, chronic hepatitis, or rare genetic disorders, such as Wilson’s disease.

Hemochromatosis

This condition causes an excess of iron to build up in the body. Too much iron can damage the liver, sometimes causing cirrhosis.

Hepatitis A

Hepatitis generally refers to a viral infection that causes liver inflammation, although there are other possible causes of hepatitis. The hepatitis virus types have different letters, including A, B, C, D, and E. Each has a different cause and severity.

Hepatitis A is more common in developing countries without clean drinking water and with poor sanitation systems. Most people can recover from hepatitis A without liver failure or long-term complications.

Hepatitis B

Hepatitis B can cause a short or long-term infection. The younger you are when infected, the higher the risk for long-term infection. While in U.S. adults the disease is most commonly spread through sexual contact, a person can also get it through sharing needles or accidentally sticking themselves with a contaminated needle.

The condition can cause serious complications, including liver failure and cancer. There’s a vaccination you can get against the disease.

Hepatitis C

Hepatitis C can be an acute or chronic infection, however the majority of acute hepatitis C infections will turn chronic. It’s most commonly spread by contact with blood containing the hepatitis C virus in it, which includes sharing contaminated needles to inject drugs or apply tattoos. Although less common, transmission through sexual intercourse can occur.

This condition can cause inflammation that can lead to cirrhosis, liver failure, and liver cancer.

Nonalcoholic fatty liver disease and NASH

These are conditions where fat builds up in the liver. An excess of fat can damage the liver, causing inflammation.

Nonalcoholic steatohepatitis (NASH) is a form of nonalcoholic fatty liver disease that causes scarring or fibrosis. People who are obese or have conditions relating to obesity, such as type 2 diabetes, are more likely to have this disease.

The liver has many functions in the body as well as an amazing capacity to regenerate itself. Without it, a person couldn’t gain energy from food or break down fats and proteins in their daily diets.

However, there are many medical conditions that can affect a person’s liver function. This is especially true if a person is a heavy drinker, as excess alcohol can place too great a strain on the liver’s functioning and lead to some of the conditions listed above.

Maintaining a healthy weight and practicing balanced eating and exercise habits can help you maintain your liver health.