@alisha-- I had liver damage due to drinking. I haven't touched a drink for ten years and my liver damage reversed itself. But when my liver was in bad shape, I remember that it was very tender. I would touch my skin and feel a slight discomfort. I also had the typical beer belly which may or may not be a sign of liver damage.
Some people don't have any symptoms, especially if the liver damage is due to disease rather than alcohol. I think it's a good idea to have a physical once a year or once every two years and check liver health after a certain age.
I'm lucky because I got rid of my bad habit without permanent damage but not everyone is so lucky. The long term effects of liver damage is no fun. I know several people who have cirrhosis from my old Alcoholics Anonymous group. They're undergoing a difficult treatment and one is being considered for a liver transplant.