Coronary heart disease is caused by the narrowing or blockage of the coronary arteries due to atherosclerosis, leading to myocardial ischemia and hypoxia. The exact cause of coronary atherosclerosis is not yet clear. Extensive research indicates that the formation of atherosclerosis involves various factors including arterial wall cells, extracellular matrix blood components, local hemodynamic environment, and genetics. Key risk factors include abnormalities in lipoproteins, hypertension, diabetes, smoking, obesity, elevated homocysteine, reduced physical activity, and old age. The condition primarily starts with damage to the endothelium and gradually progresses from there.