The liver typically contains some fat. However, if it builds up, it can cause fatty liver disease. This means that the liver is not able to function normally.

Fatty liver disease can occur when there is more than 5% fat in the liver.

This article will cover the symptoms, causes, treatment, prevention, and more for fatty liver disease.

Doctors sometimes call fatty liver disease a silent disease. This is because a person might not experience any symptoms, even as the disease progresses.

However, fatty liver disease can enlarge the liver. When this occurs, may cause pain or discomfort in the upper right side of the abdomen, which is the area between the hips and chest.

Early symptoms can include:

  • loss of appetite
  • feeling sick or vomiting
  • weight loss
  • tiredness

There are two types of fatty liver disease — nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease.

Nonalcoholic fatty liver disease

The main form of the disease is NAFLD.

In the United States, around 80–100 million individuals have NAFLD.

Two separate conditions fall under the umbrella of NAFLD: simple fatty liver, or nonalcoholic fatty liver (NAFL), and nonalcoholic steatohepatitis (NASH).

Simple fatty liver

This occurs when there is fat in the liver, but little or no damage to liver cells.

Simple fatty liver does not typically develop into a more severe medical condition.

NASH

A person who has developed NASH has inflammation and damaged liver cells, as well as fat in the liver.

NASH can progress into a more serious condition, such as liver cancer or cirrhosis.

Alcoholic fatty liver disease

People who use alcohol excessively may develop alcoholic fatty liver disease. As the liver breaks down the excess alcohol, it can generate harmful substances.

This can result in liver cell damage and inflammation.

This is the first stage of alcohol-related liver disease, and if a person stops using alcohol, they may be able to reverse it.

Alcoholic fatty liver disease can develop into alcoholic hepatitis or cirrhosis.

Cirrhosis

Cirrhosis is the most serious stage of liver disease. It typically occurs when scar tissue replaces healthy liver tissue. It can lead to liver failure.

As cirrhosis progresses, symptoms can include:

  • itchy skin
  • bruising or bleeding
  • memory problems and confusion
  • swelling in the feet or lower legs
  • bloating
  • jaundice, which is when a person’s skin and eyes turn yellow

Cirrhosis can be life threatening, and a person should seek medical help.

The cause of fatty liver disease is not entirely clear. However, genetics may play a role.

According to an article in the World Journal of Gastroenterology, specific genes may increase the chances of a person developing NAFLD by up to 27%.

Some health conditions can increase the risk of developing NAFLD.

These include:

High levels of fat in a person’s blood, such as high cholesterol and triglycerides, can also contribute to the risk of developing fatty liver disease.

Experts consider the level of triglycerides in a person’s blood to be high if it is more than 150–199 milligrams per deciliter (mg/dL).

Less common causes of fatty liver disease include hepatitis C infection, rapid weight loss, and some medications, including diltiazem and glucocorticoids.

Excess consumption of alcohol causes alcoholic fatty liver disease.

The liver breaks down alcohol and removes it from the body. As alcohol breaks down, it releases harmful toxins that can damage liver cells and cause inflammation.

There are currently no medications to treat NAFLD. Depending on the stage of the disease, however, some people can reverse it.

Gradually reducing body weight by at least 7–10% can improve disease activity.

However, losing weight too quickly can make NAFLD worse. A healthful way to lose weight gradually is with a balanced diet and regular exercise.

People who have alcoholic fatty liver disease may be able to reverse liver damage and inflammation or prevent it from getting worse by not consuming alcohol. However, this will not reverse cirrhosis.

Some people might find giving up alcohol extremely difficult, but a doctor can advise on how to do so in a safe and supported way.

Complications from NASH and alcoholic fatty liver disease can include cirrhosis and liver failure.

Medication and surgery are both treatment options at this stage.

Liver failure may require a liver transplant.

Making lifestyle changes is essential in treating fatty liver disease.

Lifestyle changes may include:

  • abstaining from alcohol
  • eating a balanced diet
  • choosing smaller portion sizes
  • doing regular exercise

Eating a balanced diet and more modest portions may help a person maintain a moderate weight.

Foods that may help prevent the development of NAFLD include garlic, coffee, leeks, asparagus, and probiotics. A person should choose whole grains and eat a wide range of fruits and vegetables.

A person should try to avoid foods that are high in saturated fats, refined carbohydrates, or sugar.

According to researchers, simple sugars, red meat, processed food, and foods that are low in fiber may lead to the development of NAFLD.

Learn more about the foods to eat or avoid for fatty liver disease here.

Taking regular exercise is also important. Aim for 2.5 hours of physical exercise per week. This should be an activity that raises the heart rate, such as going for a bike ride.

Staying active, maintaining a moderate weight, and moderate drinking can all help prevent fatty liver disease.

Acute fatty liver of pregnancy is a specific form of fatty liver disease.

Around 3% of pregnant women will develop this form of fatty liver disease.

Symptoms can include:

  • stomach pain
  • appetite loss
  • extreme tiredness
  • jaundice
  • nausea

Any pregnant woman who is experiencing these symptoms should seek urgent medical attention.

Acute fatty liver of pregnancy can be potentially life threatening, so quick diagnosis and treatment are essential.

It can be difficult for a person to know when to seek advice from a doctor because fatty liver disease often has no symptoms.

Doctors will consider a person’s medical history, diet, and lifestyle habits. They will also carry out a physical examination and do other tests to help diagnose fatty liver disease.

A physical examination may include height and weight checks to identify a person’s body mass index (BMI).

The doctor will also look for signs of jaundice and insulin resistance and check for an enlarged liver.

Blood tests can also show if a person has higher levels of specific liver enzymes.

Imaging tests, such as an ultrasound, CT scan, or MRI, can help identify fat in the liver or other signs of fatty liver disease.

A doctor may perform a biopsy. A biopsy involves inserting a needle into the liver and removing a minute sample of tissue. A laboratory technician then examines the tissue to check for disease. This minor procedure uses a local anesthetic to numb the area.

The most common risk factors for fatty liver disease relate to obesity and overweight.

Taking steps to lose weight through diet and exercise can reduce the risk of developing fatty liver disease. This can also be a way to reverse liver damage or to halt the progress of the disease.

Once fatty liver disease has progressed further, doctors find it more challenging to treat. However, the liver is very good at repairing itself, and medication and surgery may be options for treatment.

NAFLD and alcoholic fatty liver disease occur when fat builds up in the liver. This can cause the liver to stop functioning correctly.

Although fatty liver disease is often symptomless, some symptoms to look out for include weight loss, loss of appetite, and tiredness.

If the disease progresses and develops into cirrhosis, a person may experience jaundice, itching, and swelling.

The cause of fatty liver disease is unknown, but certain health conditions may contribute to its development.

Treatment is not straightforward, but a person can help or prevent fatty liver disease by maintaining a moderate weight, taking regular exercise, and not using alcohol to excess.

If a person experiences any symptoms of fatty liver disease, they should see a doctor as soon as possible.