Fatty liver disease
| Fatty liver | |
|---|---|
| Other names | Hepatic steatosis |
| Micrograph showing a fatty liver (macrovesicular steatosis), as seen in metabolic dysfunction–associated steatotic liver disease. Trichrome stain. | |
| Specialty | Gastroenterology |
| Symptoms | None, tiredness, pain in the upper right side of the abdomen |
| Complications | Cirrhosis, liver cancer, esophageal varices |
| Types | Metabolic dysfunction–associated steatotic liver disease (MASLD), alcoholic liver disease (ALD) |
| Causes | Alcohol, diabetes, obesity |
| Diagnostic method | Based on the medical history supported by blood tests, medical imaging, liver biopsy |
| Differential diagnosis | Viral hepatitis, Wilson's disease, primary sclerosing cholangitis |
| Treatment | Avoiding alcohol, weight loss |
| Prognosis | Good if treated early |
| Frequency | NAFLD: 30% (Western countries) ALD: >90% of heavy drinkers |
Fatty liver disease (FLD), also known as hepatic steatosis and steatotic liver disease (SLD), 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.
The main subtypes of fatty liver disease are metabolic dysfunction–associated steatotic liver disease (MASLD) and alcoholic liver disease (ALD), with the category "metabolic and alcohol associated liver disease" (metALD) describing an overlap of the two.
Until June 2023, MASLD and its more advanced form, metabolic dysfunction associated steatohepatits (MASH), were referred to as non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), respectively. The change in terminology was decided in a modified Delphi process led by three large pan-national liver associations (the American Association for the Study of Liver Diseases, the European Association for the Study of the Liver and the Latin American Association for the Study of the Liver).
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 MASLD develop simple fatty liver and others develop metabolic dysfunction associated steatohepatitis (MASH), which is associated with poorer outcomes. Diagnosis is based on the medical history supported by blood tests, medical imaging, and occasionally liver biopsy.
Treatment of MASLD 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. MASLD affects about 30% of people in Western countries and 10% of people in Asia. MASLD affects about 10% of children in the United States. It occurs more often in older people and males.