There are many causes of heart disease, the most common being coronary atherosclerotic heart disease, which is due to long-term hyperlipidemia leading to arteriosclerosis. After the coronary arteries harden, the lumen narrows, resulting in insufficient myocardial blood supply and the onset of coronary heart disease. Rheumatic heart disease occurs when the body is infected with streptococcus and does not receive adequate treatment, leading to an abnormal immune response that attacks the heart valves, causing valve damage. Pulmonary heart disease is caused by long-term insufficient ventilation leading to emphysema, and pulmonary hypertension increases the resistance on the heart, causing right ventricular hypertrophy.