What is fatty liver disease?
Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Fatty liver disease is a condition in which fat builds up in your liver. There are two main types:
- Nonalcoholic fatty liver disease (NAFLD)
- Alcoholic fatty liver disease, also called alcoholic steatohepatitis
What is nonalcoholic fatty liver disease (NAFLD)?
NAFLD is a type of fatty liver disease that is not related to heavy alcohol use. There are two kinds:
- Simple fatty liver, in which you have fat in your liver but little or no inflammation or liver cell damage. Simple fatty liver typically does not get bad enough to cause liver damage or complications.
- Nonalcoholic steatohepatitis (NASH), in which you have inflammation and liver cell damage, as well as fat in your liver. Inflammation and liver cell damage can cause fibrosis, or scarring, of the liver. NASH may lead to cirrhosis or liver cancer.
What is alcoholic fatty liver disease?
Alcoholic fatty liver disease is due to heavy alcohol use. Your liver breaks down most of the alcohol you drink, so it can be removed from your body. But the process of breaking it down can generate harmful substances. These substances can damage liver cells, promote inflammation, and weaken your body’s natural defenses. The more alcohol that you drink, the more you damage your liver. Alcoholic fatty liver disease is the earliest stage of alcohol-related liver disease. The next stages are alcoholic hepatitis and cirrhosis.
Who is at risk for fatty liver disease?
The cause of nonalcoholic fatty liver disease (NAFLD) is unknown. Researchers do know that it is more common in people who:
- Have type 2 diabetes and prediabetes
- Have obesity
- Are middle aged or older (although children can also get it)
- Are Hispanic, followed by non-Hispanic whites. It is less common in African Americans.
- Have high levels of fats in the blood, such as cholesterol and triglycerides
- Have high blood pressure
- Take certain drugs, such as corticosteroids and some cancer drugs
- Have certain metabolic disorders, including metabolic syndrome
- Have rapid weight loss
- Have certain infections, such as hepatitis C
- Have been exposed to some toxins
NAFLD affects about 25% of people in the world. As the rates of obesity, type 2 diabetes, and high cholesterol are rising in the United States, so is the rate of NAFLD. NAFLD is the most common chronic liver disorder in the United States.
Alcoholic fatty liver disease only happens in people who are heavy drinkers, especially those who have been drinking for a long period of time. The risk is higher for heavy drinkers who are women, have obesity, or have certain genetic mutations.
What are the symptoms of fatty liver disease?
Both NAFLD and alcoholic fatty liver disease are usually silent diseases with few or no symptoms. If you do have symptoms, you may feel tired or have discomfort in the upper right side of your abdomen.
How is fatty liver disease diagnosed?
Because there are often no symptoms, it is not easy to find fatty liver disease. Your doctor may suspect that you have it if you get abnormal results on liver tests that you had for other reasons. To make a diagnosis, your doctor will use:
- Your medical history
- A physical exam
- Various tests, including blood and imaging tests, and sometimes a biopsy
As part of the medical history, your doctor will ask about your alcohol use, to find out whether fat in your liver is a sign of alcoholic fatty liver disease or nonalcoholic fatty liver (NAFLD). He or she will also ask which medicines you take, to try to determine whether a medicine is causing your NAFLD.
During the physical exam, your doctor will examine your body and check your weight and height. Your doctor will look for signs of fatty liver disease, such as:
- An enlarged liver
- Signs of cirrhosis, such as jaundice, a condition that causes your skin and whites of your eyes to turn yellow
You will likely have blood tests, including liver function tests and blood count tests. In some cases you may also have imaging tests, like those that check for fat in the liver and the stiffness of your liver. Liver stiffness can mean fibrosis, which is scarring of the liver. In some cases you may also need a liver biopsy to confirm the diagnosis, and to check how bad the liver damage is.
Watch the video above to learn more about how diet, supplements, and lifestyle can play a role!