Coronary heart disease (CHD) is the result of blockages in the heart's blood vessels. Low blood flow to the heart due to blocked vessels causes chest pain or “angina.” If it lasts long enough, a section of heart muscle dies, a condition called myocardial infarction or “heart attack.” While many people with CHD get symptoms including chest pain or shortness of breath with exertion, others do not know that they have CHD until heart attack occurs. Risk factors for CHD include older age, male sex, high blood pressure, diabetes, smoking, high levels of total or LDL (“bad”) cholesterol and low levels of HDL (“good”) cholesterol, and family history of CHD. A patient's risk for heart attacks or angina can be determined on the basis of risk factors; several treatments are available to reduce risk for CHD events in patients at increased risk.