High LDL cholesterol can be caused by 2 factors: 1) genetic factors, such as familial hypercholesterolemia, which is often dominated by elevated LDL cholesterol; 2) secondary factors, which are mostly related to overeating and obesity; 3) metabolic diseases, such as hyperthyroidism and liver diseases, which can lead to high LDL cholesterol is high. In this case, high LDL cholesterol is a harmful cholesterol that can easily lead to atherosclerosis, and if it is coronary atherosclerosis, then plaque formation and narrowing of blood vessels may lead to coronary heart disease. If the LDL cholesterol is still high, it is necessary to control the LDL cholesterol in the normal range, so as to reduce the occurrence of cardiovascular diseases.