Fatty liver is an excessive accumulation of fat in the liver cells due to a variety of causes. Common factors include alcoholism, rapid weight loss, and malnutrition. 1. Alcoholism: Due to long-term heavy drinking, it can lead to chronic liver cell injury, which manifests as alcoholic fatty liver. With the progress of lesions, it can develop into alcoholic cirrhosis. 2. Rapid weight loss: such as fasting, excessive dieting, etc. can cause a large increase in lipolysis in a short period of time, and an increase in lipid peroxides in the liver, which can damage liver cells and lead to fatty liver. 3. Malnutrition: Insufficient protein intake or excessive lipid intake can lead to triglyceride not being able to be transported out of the liver in time, which will accumulate in the liver for a long time and form fatty liver. Other factors that can induce fatty liver are chemical poisons, lipid-lowering drugs, hormones, smoking, obesity, viral hepatitis and so on. For the formation of fatty liver, it is recommended to consult a doctor in a timely manner to analyze the specific causes in the light of individual circumstances.