Coronary artery disease: Causes, symptoms and treatment 

Coronary artery disease, otherwise known as CAD, is the most common type of heart disease in the United States, killing more men and women than anything else in the country, according to the National Library of Medicine. 

CAD is caused when the arteries that bring blood to the heart become narrowed and hardened due to a buildup of cholesterol and plaque. When the heart doesn't get the blood or oxygen it needs, it can weaken, resulting in a heart attack or even heart failure.