Jefferson University Hospitals

Frequently Asked Questions

What is fatty liver?

Fatty liver (steatosis of the liver) is one of the most common reasons people have abnormal liver blood tests. The liver is very active in handling fat. It takes lipoproteins (fats) from the blood, reworks them and secretes them in a different form. When the balance among these activities changes, fat droplets can accumulate in the liver.

What causes fatty liver?

Most often fatty liver occurs in persons who are overweight or type 2 (adult-onset) diabetes. The most important factor in fatty liver is insulin resistance. The body's sensitivity to insulin can go down with increasing body weight, age, or related to a family history of type 2 diabetes. People with increased fat around the abdomen are more likely to have insulin resistance than people with fat elsewhere. With decreased sensitivity to insulin the body must make more insulin to regulate blood sugar. High blood insulin levels cause increased blood pressure, increased triglycerides and fatty liver. Excessive alcohol intake also causes fatty liver because of the way alcohol is burned in the liver.

What signs or symptoms does fatty liver cause?

Most persons with fatty liver have no symptoms. If the liver is substantially enlarged there may be an ache or mild tenderness in the right upper abdomen. The liver blood tests are often slightly elevated, usually less than twice normal. Ultrasound of the abdomen usually shows the liver is “echogenic,” that is more dense than usual toward sound waves. The liver can also be enlarged due to fat. Ultrasound does not really measure fat, but the majority of the time an echogenic liver is found, this is related to excess fat. Excess liver fat can also be detected by MRI and CT scan.

Does excess fat hurt the liver?

At least 80% of persons with fatty liver do not develop any serious problems. If they lose weight and reduce their alcohol intake the fat goes away and the liver returns to normal. Approximately 10 to 20% of people with fatty liver can develop a more serious form of fatty liver (steatohepatitis, termed non-alcoholic steatohepatitis, or NASH) in which fat causes inflammation and fibrosis (scar tissue) in the liver. Occasionally this form of fatty liver can lead to cirrhosis and liver failure.

How do we know what is wrong with my liver?

We commonly become aware of an issue with the liver because of an abnormality on an ultrasound or because of elevated levels of AST and ALT in blood. AST and ALT are proteins or enzymes found mainly in liver cells. When they are elevated in the blood it makes us think that some type of inflammation or damage is causing the enzymes to leak out of liver cells. Fatty liver is the most common cause for this. A number of other disorders can cause chronic elevation of AST and ALT: viral hepatitis B or C, inherited liver disorders (especially iron overload and copper storage disease), autoimmune hepatitis, wheat sensitivity (celiac disease), medications or alcohol, heart failure and sometimes muscle injury.

Blood tests are usually done for autoimmune, viral and inherited liver disorders and celiac disease. Blood counts and a prothrombin time blood clotting test are usually done. The history and physical exam may point to a cause for elevated liver enzymes. If nothing is found, and if there are risk factors for fatty liver such as obesity or type 2 diabetes, then fatty liver is likely to be present. The presence of elevated blood triglycerides or low HDL cholesterol suggests insulin resistance and makes fatty liver likely.

What can be done about fatty liver?

Alcohol intake should be severely restricted. Persons who are overweight should lose weight. Exercise is beneficial alone but even more effective in combination with weight loss. Steady safe weight loss usually causes elevated liver enzymes to go down and a Mediterranean diet has been shown to be the most beneficial. In fact, fatty liver can be induced by a high-carbohydrate diet which causes high insulin levels.

Antioxidant agents such as vitamin E or milk thistle have may be beneficial, but only if recommended by your doctor. Many other medications are in development.