Fat infiltration of the liver, also called steatosis, occurs when triglycerides accumulate in liver cells. Steatosis falls into three categories: alcoholic fatty liver disease, non-alcoholic fatty liver disease, or NAFLD, and fatty liver of pregnancy. Around 20 percent of adults in the United States and almost 5 percent of children have NAFLD, the American College of Gastroenterology reports, which has a number of different causes.
Alcohol
Alcohol use is one of the main causes of fatty liver. Virtually all heavy drinkers and up to 40 percent of those who consume only modest amounts of alcohol have fatty liver, the Cleveland Clinic states. Fatty liver usually causes no symptoms and may be diagnosed during routine examination or abdominal ultrasound. Fatty liver caused by alcohol intake often reverses completely if a person's stops drinking, often within six weeks, the Merck Manual says. If the person keeps drinking heavily, fatty liver may progress to alcoholic hepatitis and then to cirrhosis.
Obesity
Obesity appears to cause NAFLD more than any other disorder, the American College of Gastroenterology states, with as many as two-thirds of obese adults and half of all obese children having fatty liver. Weight loss may help decrease fat in the liver. Fatty liver progresses to non-alcoholic steatohepatitis, or NASH, in 20 percent of obese people. NASH causes more severe liver damage with inflammation and scarring and can progress to cirrhosis and the eventual need for liver transplant.
Metabolic Syndrome
Metabolic syndrome encompasses several conditions and can lead to fatty liver from NAFLD. Excess weight, increased insulin resistance and high triglyceride levels cause fat to accumulate in the liver either by increasing the amount of fat produced or by slowing the excretion of fat. Metabolic syndrome is the most common cause of NASH, the Merck Manual notes.
Pregnancy
Between 1 in 10,000 and 1 in 15,000 women develop fatty liver in pregnancy, usually in the last trimester, the March of Dimes reports. Nausea, vomiting, stomach pain, jaundice and headache may occur. Fatty liver of pregnancy can lead to coma and may be fatal without prompt treatment. If treated, delivery of the fetus normally leads to complete resolution and no lasting harm from the condition.
