Nonalcoholic fatty liver disease

DEFINITION

Nonalcoholic fatty liver disease is a term used to describe the accumulation of fat in the liver of people who drink little or no alcohol.

Nonalcoholic fatty liver disease is common and, for most people, causes no signs and symptoms and no complications.

But in some people with nonalcoholic fatty liver disease, the fat that accumulates can cause inflammation and scarring in the liver. This more serious form of nonalcoholic fatty liver disease is sometimes called nonalcoholic steatohepatitis.

At its most severe, nonalcoholic fatty liver disease can progress to liver failure.

CAUSES

Nonalcoholic fatty liver disease occurs when your liver has trouble breaking down fats, causing fat to build up in your liver tissue.

Doctors aren’t sure what causes nonalcoholic fatty liver disease. The wide range of diseases and conditions linked to nonalcoholic fatty liver disease is so diverse that it’s difficult to pinpoint any one cause.

Types of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease can take several forms — from harmless to life-threatening. Forms include:

• 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 form, nonalcoholic fatty liver disease can cause excess liver fat, but no complications. This condition is thought to be very common.
• Nonalcoholic steatohepatitis. In a small number of people with fatty liver, the fat causes inflammation in the liver. This can impair the liver’s ability to function and lead to scarring of the liver (cirrhosis).
• Nonalcoholic fatty liver disease-associated cirrhosis. Liver inflammation leads to scarring of the liver tissue. With time, scarring can become so severe that the liver no longer functions adequately (liver failure).

SYMPTOMS

Nonalcoholic fatty liver disease usually causes no signs and symptoms. When it does, they may include:

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

When to see a doctor

Make an appointment with your doctor if you have persistent signs and symptoms that cause you concern.