What causes cirrhosis of the liver?

Alcoholic liver disease
To many people, cirrhosis of the liver is synonymous with chronic alcoholism, but in fact, alcoholism is only one of the causes. Alcoholic cirrhosis usually develops after more than a decade of heavy drinking.

The amount of alcohol that can injure the liver varies greatly from person to person. In women, as few as two to three drinks (e.g. 40g) per day have been linked with cirrhosis and in men, as few as three to four drinks (e.g. 80g) per day.

Sustained consumption of these quantities over a period of a decade, will lead to cirrhosis in susceptible persons. Alcohol seems to injure the liver by blocking the normal metabolism of protein, fats and carbohydrates.

Chronic hepatitis B, C and D
The hepatitis B virus is probably the most common cause of cirrhosis worldwide. Hepatitis B, like hepatitis C, causes liver inflammation and injury that over several decades can lead to cirrhosis. The hepatitis D virus is another virus that infects the liver, but mostly only in people who already have hepatitis B.

Autoimmune hepatitis
This type of hepatitis is caused by a problem with the immune system.

Inherited diseases
Alpha-1 antitrypsin deficiency, hemochromatosis, Wilson's disease, galactosemia, and glycogen storage diseases are among the inherited diseases that interfere with the way the liver produces, processes, and stores enzymes, proteins, metals, and other substances the body needs to function properly.

Non-alcoholic steatohepatitis (NASH)
In NASH, fat builds up in the liver and eventually causes scar tissue. This type of hepatitis appears to be associated with diabetes, protein malnutrition, obesity, coronary artery disease and corticosteroid treatment.

Blocked bile ducts
When the ducts that carry bile out of the liver are blocked, bile backs up and damages liver tissue. In babies, blocked bile ducts are most commonly caused by biliary atresia, a disease in which the bile ducts are absent or injured. In adults, the most common cause is primary biliary cirrhosis, a disease in which the ducts become inflamed, blocked and scarred.

Primary biliary cirrhosis is relatively rare. Secondary biliary cirrhosis can happen after gallbladder surgery, if the ducts are inadvertently tied off or injured.

Drugs, toxins and infections
Severe reactions to prescription drugs, prolonged exposure to environmental toxins e.g. organic solvents (dry cleaners, spray painters, refinery workers) or toxins (chemical industry, farm workers). The parasitic infection schistosomiasis, and repeated bouts of heart failure with liver congestion may each lead to cirrhosis.