When the liver is under attack from viruses, or from chemical poisons like alcohol, it can respond by forming scar tissue. Cirrhosis refers to structural changes to the liver caused by continual scarring.

There are various stages or degrees of cirrhosis. When cirrhosis is advanced, blood cannot flow through the liver properly and the liver is unable to function adequately. Severe cirrhosis can be fatal. People with cirrhosis also have an increased chance of developing liver cancer.