The key enzyme for cholesterol synthesis is beta-hydroxy-beta-methylglutaric acid monoacyl coenzyme A. As we know from the cholesterol synthesis pathway, cholesterol can be used to store blood lipids and is also an essential raw material for hormone synthesis. Once cholesterol is synthesized, part of it is stored as energy in the liver as well as in the subcutaneous tissues for emergency use. Another part is then further metabolized and involved in the synthesis of sex hormones, corticosteroids, etc. In lean patients, on the one hand, fat mobilization in the body will increase, resulting in increased cholesterol breakdown to meet the body’s essential energy requirements. On the other hand, the patient’s hormone levels will be relatively low and more likely to have abnormal hormone levels. Therefore, cholesterol is not as low as possible. Too low can lead to insufficient stored energy and insufficient raw materials for hormone synthesis, which can lead to hormone loss. It is usually recommended to keep cholesterol in the right range and also to control the enzymes that limit cholesterol synthesis. If the relevant enzyme is deficient or if the enzyme is abnormal, it can also lead to abnormal cholesterol synthesis and hyperlipidemia. Hyperlipidemia in this case is not caused by an excessive diet.