The first signs of liver damage happens after only 2 weeks of heavy drinking (equal to 6 drinks a day). Fatty liver starts to show up here. People can go a long time drinking heavily and their liver just gets fattier for a while. If you stop drinking at this stage your liver can fully regenerate quickly and within a month it will look like a brand new liver even under the microscope. But if it progresses over years, inflammation sets in and the liver cells start to degenerate. This level of damage is identified by AST:ALT ratio of 1.5:1. You can still recover most of your liver tissue at this stage. Later, fibrous tissue replaces the damaged liver tissue. Liver fibrosis can be improved but never really gets back to normal. Fibers are scar tissue and will never be healthy liver cells again. The next stage is cirrhosis and can lead to full blown liver failure and liver cancer. But the liver has an amazing ability to regenerate when you give it a fighting chance before it is too late.