Fatty liver and fatty infiltration are two different concepts. Fatty liver often develops as a result of excessive fat infiltration, while fatty infiltration simply indicates excessive fat deposits in the liver, which may change if metabolized in a timely manner. Long-term fat infiltration may cause the formation of fatty liver, which is caused by various etiologies, such as medication, alcohol, and obesity due to long-term diet. These are all causes of fatty liver formation, mainly due to fatty degeneration of liver cells. It is important to check liver function, blood lipids and liver ultrasound regularly, and intervention is needed if abnormal liver function is present. If there is only simple fatty infiltration, it can be improved by exercise and diet.