The liver, the largest organ in the body, is essential in keeping the body functioning properly. It removes or neutralizes poisons from the blood, produces immune agents to control infection, and removes germs and bacteria from the blood. It makes proteins that regulate blood clotting and produces bile to help absorb fats and fat-soluble vitamins. You cannot live without a functioning liver.

In cirrhosis of the liver, scar tissue replaces normal, healthy tissue, blocking the flow of blood through the organ and preventing it from working as it should. Cirrhosis is the twelfth leading cause of death by disease, killing about 26,000 people each year. Also, the cost of cirrhosis in terms of human suffering, hospital costs, and lost productivity is high.

Cirrhosis has many causes. In the United States, chronic alcoholism and hepatitis C are the most common ones.

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 per day have been linked with cirrhosis and in men, as few as three to four drinks per day. Alcohol seems to injure the liver by blocking the normal metabolism of protein, fats, and carbohydrates.

Chronic hepatitis C.
The hepatitis C virus ranks with alcohol as a major cause of chronic liver disease and cirrhosis in the United States. Infection with this virus causes inflammation of and low grade damage to the liver that over several decades can lead to cirrhosis.

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

Autoimmune hepatitis.
This disease appears to be caused by the immune system attacking the liver and causing inflammation, damage, and eventually scarring and cirrhosis.

Inherited diseases.
Alpha-1 antitrypsin deficiency, hemochromatosis, Wilson 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.

Nonalcoholic 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 treatment with corticosteroid medications.

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. 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, the parasitic infection schistosomiasis, and repeated bouts of heart failure with liver congestion can all lead to cirrhosis.

Many people with cirrhosis have no symptoms in the early stages of the disease. However, as scar tissue replaces healthy cells, liver function starts to fail and a person may experience the following symptoms:

• exhaustion
• fatigue
• loss of appetite
• nausea
• weakness
• weight loss
• abdominal pain
• spider-like blood vessels (spider angiomas) that develop on the skin

As the disease progresses, complications may develop. In some people, these may be the first signs of the disease.