See below. 1. Alcohol 2. Hepatitis c & b 3. Others like fatty liver disease, alpha-1 antitrypsin deficiency, inflammatory bowel disease (includes ulcerative colitis and crohns - usually crohns), primary biliary cirrhosis, primary sclerosing cholangitis, tylenol (acetaminophen) or aflatoxin (certain mushrooms) toxicity but usually causes immediate failure, parasites, and others.
Several things. Including the now most common - hepatitis c, worldwide it is hepatitis b - and the second most common in the west, which is alcohol. There are rare cases of other liver diseases, including the genetic wilson's disease and primary biliary cirrhosis, and also rare cases of autoimmune hepatitis causing cirrhosis. The combination of hep c and alcohol is especially bad. Rarely, other drugs and toxins.