What cause liver damage?

Many things: Many things. Alcohol, infections ( hepatitis) medications, toxins. It's a lengthy list.

Multiple causes: There are many causes of liver damage. Excess alcohol use is a major cause. Hepatitis and abnormal iron storage can also be the reason. Fat storage in the liver may be a problem if it becomes extensive. Autoimmune diseaes is also a possibility. If you have abnormal liver tests or suspect a problem, you should discuss the situation with your doctor now.

Many causes.: there are entire text books written on possible causes of liver damage. The most common causes in the United States are alcohol, viruses, medications, genetic, and autoimmune processes. Each of these can damage the liver in various ways. If you feel you have liver damage, see your doctor. They may recommend that you see a gastroenterologist also. Good luck.