Liver damage caused by fatty liver usually takes more than three months, which often depends on a number of factors such as the extent of liver damage and the aggressiveness of treatment. Clinically, fatty liver is categorized into mild, medium and severe according to the amount of fat. 1. Mild fatty liver, the amount of fat more than 5%, often appear loss of appetite, nausea and vomiting, the liver area stuffy discomfort or pain, jaundice and other symptoms, the degree of liver damage is relatively mild, active control of diet, exercise and liver protection treatment, generally about a week is possible to recover. 2. Moderate fatty liver, the amount of fat is more than 10%, most of them are caused by overweight or long-term heavy drinking, active physical exercise, control drinking, if the control situation is good, there is a chance to recover within half a year, if not actively treated, it may take 1~2 years, or even longer, and there is a possibility of developing into liver cirrhosis. 3. Severe fatty liver, the amount of fat is more than 25%, easy to trigger cirrhosis and other lasting abnormalities of liver function, at this time, actively protect the liver treatment, reduce the causative factors, in order to slowly carry out the recovery of liver function. In conclusion, facing the liver injury caused by fatty liver, only actively cooperate with doctors, control under professional guidance, can effectively recover liver function.