Division of Gastroenterology

Information About Liver Disease for Patients

The liver is a vital organ important in the following functions:

  • Removal of harmful chemicals from blood
  • Fighting infection
  • Food digestion
  • Nutrients and Vitamins storage
  • Energy Storage

What is NAFLD?

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common liver disease in the United States. The causes of NAFLD are unknown, but are likely to involve many factors ranging from genetic characteristics to personal lifestyle. It commonly occurs in the setting of obesity, insulin resistance, and a sedentary lifestyle, and it is often considered to be the liver manifestation of the metabolic syndrome. Patient may have elevated blood lipids, diabetes or are pre-diabetic. Some factors (risk factors) may increase the chance of developing NAFLD, while other factors (protective factors) may decrease the chance of developing NAFLD. The factors that determine whether a patient progresses from NAFLD to more severe liver disease are also unknown. The time it takes for a patient to progress to more severe disease is also uncertain. Several factors are possible candidates for the underlying reasons for liver injury:

  • Insulin resistance
  • Release of toxic inflammatory proteins by fat cells
  • Oxidative stress inside liver cells

What is NASH?

The term NAFLD covers a range of liver disease progression. When fatty liver disease moves on to a more severe level of liver injury, it is called Nonalcoholic Steatohepatitis (NASH). Non-Alcoholic Steatohepatitis (NASH) has become the most common form of chronic liver disease in the developed world. NAFLD/NASH is likely the most common liver disease in the United States and is thought to be related to obesity or diabetes. Estimates of the prevalence of NAFLD in adults range from 17% to 46%. NASH has been found in 3-13% of adults, with its prevalence approaching 50% in patients with severe obesity and diabetes.

NASH is usually first suspected by observing elevations in liver enzymes such as alanine aminotransferase (ALT) or aspartate aminotransferase (AST). Currently, the only way to prove a diagnosis of NASH is through a liver biopsy (small amount of liver tissue removed by needle). The biopsy results may show different amounts of fat, inflammation (swelling), and scarring in the liver. NASH can lead to severe liver disease in some patients.

What are the symptoms of NASH and NAFLD?

NASH is usually a disease with few or no symptoms. NASH often resembles alcoholic fatty liver but occurs in people who drink little or no alcohol. Patients with NASH usually will have fat, inflammation and damage in the liver. Since NASH is a “silent” liver disease, most patients feel well and nor usually unaware of their condition.

Once the disease is more advanced or cirrhosis develops, the patient may experience symptoms such as fatigue, weight loss, and weakness. The progression of NASH can take years but can be stop or reversed without specific therapy. NASH can slowly become worse, causing scarring or “fibrosis” to appear in the liver. When fibrosis becomes worse, cirrhosis develops causing severe scarring and hardening of the liver. Once the liver is cirrhotic, few treatments can prevent the progression. A cirrhotic patient may experience fluid retention, bleeding from the intestines, muscle wasting and liver failure. Currently, liver transplantation is the only treatment for advanced cirrhosis with liver failure.