Fatty Liver

Other names: hepatic steatosis or steatohepatitis

Fatty liver is one of the most common liver diseases in Western countries. In this condition fat accumulates in liver cells (hepatocytes), causing cell enlargement (fatty liver or steatosis) and sometimes damage to the cell (steatohepatitis). The damage is often minor although a small proportion of patients with steatohepatitis develop liver fibrosis and cirrhosis.

Cause of Fatty Liver

The main causes of fatty liver include obesity, high dietary intake of saturated fats, excessive alcohol consumption, and diabetes mellitus. Liver damage associated with fatty liver is common in people who drink alcohol excessively (alcoholic steatohepatitis), but also occurs in the absence of excessive alcohol (non-alcoholic steatohepatitis or NASH). Less common causes include pregnancy, some medications (eg. corticosteroids), and many metabolic and other diseases.


The typical patient with fatty liver is overweight, eats too much (particularly fatty food), drinks too much alcohol, and does not exercise enough. Usually the symptoms are minor (discomfort in the upper abdomen on the right side), or there may be no symptoms. Often the only abnormality is raised liver enzymes.


The diagnosis is usually made by recognising the typical clinical presentation and excluding other diseases such as chronic viral hepatitis, autoimmune chronic active hepatitis, haemochromatosis, and reactions to medications. If there are minimal symptoms, there is no evidence or liver dysfunction or failure, and the liver enzymes are only mildly raised, it may be adequate to advise dietary and other changes and observe the patient.

A liver biopsy is required if there is any doubt of the diagnosis, or if there is clinical and laboratory evidence of significant liver dysfunction. An ultrasound of the liver is useful, demonstrating increased echogenicity (increased density of the echos reflected from the liver)and excluding tumours and biliary obstruction. However, fatty liver is not the only cause of increased echogenicity (excess iron is another).

Medical Treatment

Fatty liver is often a lifestyle disorder and treatment involves counselling about diet, weight reduction, and a safe level of alcohol consumption. It is important to test for and treat diabetes mellitus. The outlook for most patients is good, although it is common for some degree of liver enzyme abnormality to remain, and a small proportion of patients will develop cirrhosis.