What risks are associated with oral contraceptives?

Oral contraceptives pose a risk for heart disease because they raise slightly the level of LDL cholesterol while at the same time lowering the level of HDL. However, among nonsmoking women under forty who take birth control pills, there is only a slight increase in the risk of heart disease. But when women in the same age group smoke, are overweight, and take birth control pills, they are about five times more likely to suffer a heart attack.