Most liver diseases, including fatty liver, cirrhosis, primary biliary cirrhosis and primary sclerosing cholangitis, result from injury to the liver. If damage is acute (sudden) and limited, the liver commonly repairs itself by regenerating new liver cells onto the scaffolding (internal structure) left when liver cells die. Repair and full recovery occur if the person can survive long enough to allow this renewal. However, repeated damage, particularly with disruption of the liver scaffolding, leads to scarring (fibrosis) and erratic attempts at regenerating, resulting in cirrhosis.

Injury to the liver can follow exposure to any of the following:

• Alcohol (a common cause)
• Toxins in the environment and as contaminants in foods
• Certain drugs, such as aspirin (given to infants), corticosteroids, tamoxifen, and tetracycline
• Some medicinal herbs (for example, bush tea, which contains pyrrolizidine alkaloids)
• Metabolic problems
• Certain viral infections
• Inflammation due to malfunction of the immune system, causing the body to attack its own tissues (an autoimmune reaction—see Allergic Reactions and Other Hypersensitivity Disorders: Autoimmune Disorders)

Sometimes the exact cause of liver injury is not known.

Last full review/revision September 2007 by Eldon A. Shaffer, MD