What is the liver’s function?

Your liver is an essential organ with multiple life-supporting functions. The liver:

  • Produces bile, which helps with digestion.
  • Makes proteins for the body.
  • Stores iron.
  • Converts nutrients into energy.
  • Creates substances that help your blood clot (stick together to heal wounds).
  • Helps you resist infections by making immune factors and removing bacteria and toxins (substances that can harm your body) from your blood.

What is fatty liver disease?

Fatty liver disease (steatosis) is a common condition caused by having too much fat build up in your liver. A healthy liver contains a small amount of fat. It becomes a problem when fat reaches 5% to 10% of your liver’s weight.

Why is fatty liver disease bad?

In most cases, fatty liver disease doesn’t cause any serious problems or prevent your liver from functioning normally. But for 7% to 30% of people with the condition, fatty liver disease gets worse over time. It progresses through three stages:

  1. Your liver becomes inflamed (swollen), which damages its tissue. This stage is called steatohepatitis.

  2. Scar tissue forms where your liver is damaged. This process is called fibrosis.

  3. Extensive scar tissue replaces healthy tissue. At this point, you have cirrhosis of the liver.

Cirrhosis of the liver

Cirrhosis of the liver is a result of severe damage to the liver. The hard scar tissue that replaces healthy liver tissue slows down the liver’s functioning. Eventually, it can block liver function entirely. Cirrhosis can lead to liver failure and liver cancer.

What are the forms of fatty liver disease?

There are two main forms of fatty liver disease:

Alcoholic liver disease

Alcoholic fatty liver is the accumulation of fat in the liver as a result of heavy drinking. (Moderate drinking is defined as one drink a day for women and up to two drinks per day for men.) About 5% of people in the U.S. have this form of liver disease.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease occurs in people who aren’t heavy drinkers. The condition affects one in three adults and one in 10 children in the United States. Researchers haven’t found the exact cause of nonalcoholic fatty liver disease. Several factors, such as obesity and diabetes, can increase your risk.

Who gets fatty liver disease?

You have a greater chance of developing fatty liver disease if you:

  • Are Hispanic or Asian.
  • Are a postmenopausal woman (a woman whose periods have stopped).
  • Have obesity with a high level of belly fat.
  • Have high blood pressure, diabetes, or high cholesterol.
  • Have obstructive sleep apnea (a blocked airway that causes breathing to stop and start during sleep).

What causes fatty liver disease?

Some people get fatty liver disease without having any pre-existing conditions. But these risk factors make you more likely to develop it:

What are the symptoms of fatty liver disease?

People with fatty liver disease often have no symptoms until the disease progresses to cirrhosis of the liver. If you do have symptoms, they may include:

  • Abdominal pain or a feeling of fullness in the upper right side of the abdomen (belly).
  • Nausea, loss of appetite or weight loss.
  • Yellowish skin and whites of the eyes (jaundice).
  • Swollen abdomen and legs (edema).
  • Extreme tiredness or mental confusion.
  • Weakness.

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