Fatty liver disease (FLD), also known as hepatic steatosis, is a condition where excess fat builds up in the liver. Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications may include cirrhosis, liver cancer, and esophageal varices.There are two types of fatty liver disease: non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. NAFLD is made up of simple fatty liver and non-alcoholic steatohepatitis (NASH). The primary risks include alcohol, type 2 diabetes, and obesity. Other risk factors include certain medications such as glucocorticoids, and hepatitis C. It is unclear why some people with NAFLD develop simple fatty liver and others develop NASH. Diagnosis is based on the medical history supported by blood tests, medical imaging, and occasionally liver biopsy.Treatment of NAFLD is generally by dietary changes and exercise to bring about weight loss. In those who are severely affected, liver transplantation may be an option. More than 90% of heavy drinkers develop fatty liver while about 25% develop the more severe alcoholic hepatitis. NAFLD affects about 30% of people in Western countries and 10% of people in Asia. NAFLD affects about 10% of children in the United States. It occurs more often in older people and males. Signs and symptoms
Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications
Fatty liver can develop into a fibrosis or a liver cancer.
The serum alanine transaminase (ALT) level usually is greater than the aspartate transaminase (AST) level in the nonalcoholic variant and the opposite in alcoholic FLD (AST:ALT more than 2:1). Simple blood test may help to determine the magnitude of the disease by assessing the degree of liver fibrosis. For example, AST-to-platelets ratio index (APRI score) and several other score, calculated from the results of blood test, can detect the degree of liver fibrosis and predict the future formation of liver cancer.Imaging studies are often obtained during the evaluation process. Ultrasonography reveals a "bright" liver with increased echogenicity. Medical imaging can aid in diagnosis of fatty liver; fatty livers have lower density than spleens on computed tomography (CT), and fat appears bright in T1-weighted magnetic resonance images (MRIs). Magnetic resonance elastography, a variant of magnetic resonance imaging, is investigated as a non-invasive method to diagnose fibrosis progression. Histological diagnosis by liver biopsy is the most accurate measure of fibrosis and liver fat progression as of 2018. Conventional imaging methods, such as ultrasound, CT and MRI, are not specific enough to detect fatty liver disease unless fat occupies at least 30% of the liver volume. Treatment
Decreasing caloric intake by at least 30% or by approximately 750–1,000 kcal/day results in improvement in hepatic steatosis. For people with NAFLD or NASH, weight loss via a combination of diet and exercise was shown to improve or resolve the disease.