People with fatty liver may feel tired or have mild abdominal discomfort but otherwise have no symptoms.
Sometimes fatty liver causes advanced liver disease such as fibrosis and cirrhosis.
A liver biopsy may be needed to confirm the diagnosis and to determine the cause and extent of the damage.
Doctors focus on controlling or eliminating the cause of fatty liver, such as metabolic syndrome or consumption of large amounts of alcohol.
(See also Overview of Liver Disease Overview of Liver Disease Liver disease can manifest in many different ways. Characteristic manifestations include Jaundice (a yellowish discoloration of the skin and whites of the eyes) Cholestasis (reduction or stoppage... read more .)
The fatty liver may or may not be inflamed. Inflammation of the liver due to fatty liver is called steatohepatitis. This inflammation may develop into scarring (fibrosis Fibrosis of the Liver Fibrosis is the formation of an abnormally large amount of scar tissue in the liver. It occurs when the liver attempts to repair and replace damaged cells. Many conditions can damage the liver... read more ). Fibrosis often progresses to cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more (scarring that distorts the structure of the liver and impairs its function).
Fatty liver (with or without fibrosis) due to any condition except consumption of large amounts of alcohol is called nonalcoholic fatty liver disease (NAFLD). NAFLD develops most often in people with at least one of the components of metabolic syndrome:
Excess body weight
High fat levels in the blood (triglyceride and cholesterol)
Inflammation of the liver due to NAFLD is called nonalcoholic steatohepatitis (NASH). This inflammation may develop into scarring (fibrosis) and cirrhosis.
Causes of Fatty Liver
The most common causes of fatty liver in the United States and other Western countries are
Metabolic abnormalities, such as excess body weight, insulin resistance (as can occur in diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more ), and high levels of fats (triglycerides and cholesterol) in the blood
Certain drugs, including corticosteroids, tamoxifen, and certain chemotherapy drugs
Hereditary metabolic disorders
The combination of excess body weight, insulin resistance, and high triglyceride levels is called metabolic syndrome Metabolic Syndrome Metabolic syndrome is characterized by a large waist circumference (due to excess abdominal fat), high blood pressure, resistance to the effects of insulin (insulin resistance) or diabetes,... read more . All of these conditions cause fat to accumulate in liver cells by causing the body to synthesize more fat or by processing (metabolizing) and excreting fat more slowly. As a result, fat accumulates and is then stored inside liver cells. Just consuming a high-fat diet does not result in fatty liver.
Rarely, fat accumulates in the liver during late pregnancy. This disorder, called fatty liver of pregnancy Fatty liver of pregnancy Some liver disorders occur only during pregnancy. Others (such as gallstones, cirrhosis, or hepatitis) may have been present before the pregnancy, or they may occur coincidentally with the pregnancy... read more or microvesicular steatosis, is usually considered a different disorder from fatty liver.
Did You Know...
Symptoms of Fatty Liver
Fatty liver usually causes no symptoms. Some people feel tired or have vague abdominal discomfort. The liver tends to enlarge and can be detected by doctors during a physical examination.
Diagnosis of Fatty Liver
Imaging tests, such as ultrasonography
Sometimes a liver biopsy
If doctors suspect fatty liver, they ask about alcohol use. This information is crucial. Continued and excessive alcohol use can cause severe liver damage.
Blood tests to detect liver abnormalities Liver Blood Tests Liver tests are blood tests that represent a noninvasive way to screen for the presence of liver disease (for example, hepatitis in donated blood) and to measure the severity and progress of... read more , such as inflammation, are important because inflammation may lead to cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more . Additional blood tests help exclude other causes of liver abnormalities, such as viral hepatitis. Ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI) of the abdomen can detect excess fat in the liver but cannot always determine whether inflammation or fibrosis is present (see Imaging Tests of the Liver and Gallbladder Imaging Tests of the Liver and Gallbladder Imaging tests of the liver, gallbladder, and biliary tract include ultrasonography, radionuclide scanning, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic retrograde cholangiopancreatography... read more ). Additionally, new imaging tests such as magnetic resonance elastography (MRE) or ultrasound elastrography can determine if scar tissue or cirrhosis is present. However, in obese people, the fibrosis score can sometimes be falsely elevated due to high fat content, and people may need a liver biopsy Biopsy of the Liver Doctors can obtain a sample of liver tissue during exploratory surgery, but more often they obtain a sample by inserting a hollow needle through the person's skin and into the liver. This type... read more .
Liver biopsy is the most accurate test and may be necessary to confirm the diagnosis. For the biopsy, a doctor gives a local anesthetic to lessen any pain, then inserts a long hollow needle through the skin and into the liver to obtain a small piece of liver tissue for examination under a microscope. The biopsy can help determine whether fatty liver is present, whether it resulted from alcohol or certain other specific causes, and how severe the liver damage is.
Prognosis of Fatty Liver
Excess fat in the liver by itself is not necessarily a serious problem. For example, if alcohol is the cause, the fat can disappear, usually within 6 weeks, when people stop drinking. However, if the cause is not identified and corrected, fatty liver can have serious consequences. For example, if people continue to drink large amounts of alcohol or if a drug causing fatty liver is not stopped, repeated liver injury may eventually lead to cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more .
Treatment of Fatty Liver
Control or elimination of the cause
Treatment of fatty liver focuses on controlling or eliminating the cause of fatty liver. For example, people should
Stop taking any drug that could be causing fatty liver
Take measures to control diabetes or lower triglyceride levels
Stop drinking alcohol
A decrease in body weight of 5% can decrease fat content in the liver, a 7% decrease can reduce inflammation and nonalcoholic steatohepatitis, and a 10% decrease can help reverse scarring and fibrosis.
Doctors sometimes try giving vitamin E and thiazolidinediones (a class of drugs, including rosiglitazone and pioglitazone, that are used to treat diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more ) to treat fatty liver that is not caused by alcohol. However, specialists are using these drugs less often because they often cause adverse effects and may not make a difference in the long-term. New drug treatments are being developed in clinical trials. Doctors can refer people to a liver specialist (hepatologist) to discuss whether they would be a good candidate for these new drugs.