Cirrhosis - Causes

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease, also called nonalcoholic steatohepatitis (NASH), has features similar to alcohol-induced hepatitis, particularly a fatty liver, but it occurs in individuals who do not consume significant amounts of alcohol. Severe obesity and type 2 diabetes are the major risk factors for NASH, as well as for complications from NASH. NASH may occur in about half of people with diabetes and up to 75% of obese people, depending on how severe the obesity is. (It can occur in overweight children as well as adults.) Some evidence suggests that insulin resistance (the primary problem in type 2 diabetes) is a major factor in development of a fatty liver in the first place. Although NASH is generally considered to be a benign and slowly progressive disorder, the fatty liver is vulnerable to injury from oxidants (damaging particles produced by chemical processes in the body). Excessive oxidation can lead to progression to advanced liver disease. In one study of patients with NASH, about 20% had some liver damage over a period of 3.5 to 11 years, with only about 6% of all patients showing severe liver damage. Another study reported that eventually 15% to 20% of patients develop advanced liver disease.

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Hemochromatosis and Iron Overload

Hemochromatosis is a disorder of iron metabolism that is characterized by excess iron deposits throughout the body, including the liver, where they can cause cirrhosis. Once believed to be rare, hereditary hemochromatosis is now considered to be one the most common genetic diseases among Caucasians. Between 2% and 4% of people of European ancestry are believed to carry the gene, and the disease itself is estimated to occur in between 1.5 and three Caucasians per 1,000. Early symptoms of hemochromatosis include:

Fatigue.
Joint pain (arthralgia).
Impotence in men.
Arthritis.

A 2000 study further suggested that both hemochromatosis patients and their relatives who carry the trait are at higher risk for cirrhosis. Elevated iron levels, even in the absence of this disease, have been associated with liver scarring, particularly when accompanied by other risk factors for cirrhosis, including hepatitis, NASH, and alcoholism.

Other Causes of Cirrhosis

Inherited Diseases. Cirrhosis can be caused by a number of inherited diseases including:

Cystic fibrosis.
Alpha-1 antitrypsin deficiency.
Galactosemia.
Glycogen storage diseases.
Wilson's disease.

Other Rare Causes. Rare causes of cirrhosis include:

Schistosomiasis, caused by a parasite found in the Far East, Africa, and South America.
Small intestine bypass surgery (rarely, if ever, performed anymore).
Long-term or high level exposure to certain chemicals and drugs can cause cirrhosis, including arsenic, methotrexate, and toxic doses of vitamin A.

Changes That Resemble Cirrhosis

Cancers that have metastasized to the liver, blood clots in the hepatic or portal vein, or obstructions in the bile duct can cause changes that resemble cirrhosis.