Fatty liver is the build-up of fat in the liver cells. Although this is not a normal condition, fat in the liver usually causes no damage by itself. However, on some occasions it can be a sign that other more harmful conditions are developing. Fatty liver may be associated with or lead to inflammation of the liver. Liver inflammation can cause scarring and hardening of the liver. When scarring becomes extensive, it is called cirrhosis, and this is a very serious condition. Therefore, it is important that a physician thoroughly examine a patient with a fatty liver.

It would seem logical that eating fatty foods would cause a fatty liver, but this is not the case. The liver plays an important role in the metabolism or breakdown of fats. Something goes wrong in the process of metabolism, but it is still unknown what causes fat to build-up in the liver.

It is known that fat accumulates in the liver with a number of conditions. The most common is obesity. Fatty liver is also associated with diabetes mellitus, high blood triglycerides, and the heavy use of alcohol. It may occur with certain illnesses such as tuberculosis, malnutrition, intestinal bypass surgery for obesity, excess vitamin A in the body, or the use of certain drugs such as valproic acid (trade names: Depakene/Depakote) and corticosteroids (cortisone, prednisone). Sometimes fatty liver can occur as a complication of pregnancy.

There are usually no symptoms that are noticeable to the patient. In fact, fatty liver is frequently uncovered during a routine physical examination. There may be a rise in certain liver enzymes found in the blood, and sometimes the liver is slightly enlarged. Fatty liver may also be discovered while the physician is evaluating a patient for other illnesses. For example, an ultrasound exam of the abdomen done for other reasons may show fat in the liver. To be certain of a diagnosis of fatty liver, the physician may recommend a liver biopsy. Under local anesthesia, a slender needle is inserted through the right lower chest and a small piece of liver tissue is taken out with the needle and examined under a microscope.

Steatohepatitis is inflammation of the liver related to fat accumulation. Heavy alcohol use can lead to fatty liver and inflammation, usually called alcoholic hepatitis. Steatohepatitis resembles alcoholic hepatitis, but can occur in people who seldom or never drink alcohol. In this instance, it is often called nonalcoholic steatohepatitis or NASH. Both alcoholic hepatitis and steatohepatitis can lead to serious liver damage and cirrhosis.

Studies have shown that many people who are significantly overweight have developed, or will develop, steatohepatitis. It can also occur with rapid weight loss. Steatohepatitis has been connected to estrogen hormones in some women.

When diabetes is not properly controlled, diabetes mellitus, researchers believe steatohepatitis may develop.

In most instances treatment of fatty liver and steatohepatitis requires control of the underlying conditions. This may include reduction of high blood triglycerides, good control of diabetes, or not drinking alcohol. In some cases, surgery is required to reverse intestinal bypass.

Since being overweight is by far the most critical factor, weight loss is the key to ridding the liver of fat. This is especially necessary if liver damage is occurring, and early signs of scarring are present on the biopsy. High blood triglycerides and diabetes are also increasing risks with obesity. Therefore, when steatohepatitis is present with these conditions, losing weight has even greater benefits. Losing weight can be difficult; however, it must be done because the alternative may lead to cirrhosis and the need for a liver transplant.

Liver transplantation can be a way to treat those with chronic, severe liver damage. Advances in surgical techniques and the use of new drugs to suppress rejection have dramatically improved the success rate. Steatohepatitis is one of the more uncommon reasons for a liver transplant. Survival rates at transplant centers are excellent with a good quality of life after recovery.