Fatty liver is not always considered hepatic insufficiency, hepatic insufficiency refers to the serious damage to liver cells, resulting in significant decreases in liver function, such as decreased synthetic capacity of the liver, decreased biliary effect, decreased biotransformation function, and significant decreases in metabolic functions such as glucose metabolism, lipid metabolism, and vitamins, resulting in various functional decreases leading to pathological manifestations. For example, the decreased synthetic capacity of the liver is manifested by reduced albumin synthesis and hypoproteinemia, leading to ascites, hydrothorax, and lower limb edema. If the cholestatic effect is reduced, jaundice can occur. Glucose metabolism is abnormal and elevated blood glucose occurs, which leads to diabetes. Fatty liver is defined as steatosis of liver cells. In mild fatty liver, liver function can be normal without significant liver cell damage. In case of moderate fatty liver, slight damage to liver cells can occur and liver function is usually mildly abnormal, but not up to the level of liver insufficiency. If severe fatty liver or fatty cirrhosis is present, liver insufficiency can occur.