Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a term used to describe the accumulation of fat in the liver of people who drink little or no alcohol.  NAFLD is common and, for most people, causes no signs and symptoms and no complications.  In some individuals however the fat that accumulates in the liver can cause inflammation and scarring. This more serious form of NAFLD is sometimes called nonalcoholic steatohepatitis (NASH).  In its most severe form, NAFLD can progress to liver failure.

Causes of NAFLD

According to the American Liver Society NAFLD affects up to 25% of people in the United States.  NAFLD occurs when your liver has trouble breaking down fats, causing fat to build up in your liver tissue.  Doctors aren't sure what causes NAFLD but it tends to develop in individuals who are overweight, or have diabetes, high cholesterol or high triglycerides. Rapid weight loss and poor eating habits also may lead to development of NAFLD.

There are other diseases and conditions that appear to increase your risk of NAFD, however some people develop NAFLD even if they do not have any of these conditions..

  • Gastric bypass surgery
  • Metabolic syndrome
  • Obesity
  • Polycystic ovary syndrome
  • Sleep apnea
  • Type 2 diabetes
  • Underactive thyroid (hypothyroidism)
  • Underactive pituitary gland (hypopituitarism)

What Are the Symptoms of NAFLD?

NAFLD usually causes no signs or symptoms. NAFLD is typically suspected when blood tests show high levels of liver enzymes, which are often identified when performing routine blood tests.

When symptoms occur they may include:

  • Fatigue
  • Pain in the upper right abdomen
  • Weight loss

How is NAFLD Diagnosed?

Tests and procedures used to diagnose nonalcoholic fatty liver disease include:

  • Blood tests. Liver function tests, including tests of liver enzymes can be easily measured in the blood. 
  • Imaging procedures. Imaging procedures used to diagnose fatty liver disease include ultrasound, computerized tomography (CT) scan and magnetic resonance imaging (MRI).
  • Liver tissue testing. If it's suspected that you have a more serious form of nonalcoholic fatty liver disease, your doctor may recommend a liver biopsy in order to remove a sample of tissue from your liver. The sample can be examined in a laboratory to look for signs of inflammation and scarring.
  • NAFLD-Nonalcoholic fatty liver. It's not normal for fat to build up in your liver, but it won't necessarily hurt you. In its simplest and most common form, NAFLD can cause excess liver fat, but no complications.

Types of NAFLD.

  • NASH-Nonalcoholic steatohepatitis.  In a small number of individuals the fat causes inflammation in the liver. This inflammation can impair the liver's ability to function and lead to cirrhosis or scarring of the liver.  This more severe form of NAFLD is called NASH. NASH causes the liver to swell and become damaged.

NASH is one of the leading causes of cirrhosis in adults in the United States.  It is estimated that up to 25% of adults with NASH may have cirrhosis.  Most individuals with NASH are between the ages of 40 and 60 years and NASH is more common in women than in men.

  • NAFLD or NASH associated cirrhosis. Liver inflammation may occasionally lead to scarring of the liver tissue. This scaring, also referred to as cirrhosis can become so severe that the liver no longer functions adequately and liver failure occurs. 

How is NAFLD Treated?

There is currently no standard medical treatment for NAFLD. Doctors try to determine what risk factors might contribute to NAFLD in each individual and work to modify those factors. For instance, if an individual is overweight or has high cholesterol your doctor will help you to lose weight and lower your cholesterol through diet, exercise and, in some cases, medications and surgery.

Avoiding additional conditions that can contribute to liver disease is also recommend.  Your doctor may recommend you receive vaccinations against hepatitis A and B, and reduce or avoid alcohol consumption to help protect your liver from further damage.