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 this. 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. At 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 complications.
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).