What Causes Coronary Artery Disease?

Research suggests that coronary artery disease (CAD) starts when certain factors damage the inner layers of the coronary arteries. These factors include:

• Smoking
• High amounts of certain fats and cholesterol in the blood
• High blood pressure
• High amounts of sugar in the blood due to insulin resistance or diabetes

When damage occurs, your body starts a healing process. Excess fatty tissues release compounds that promote this process. This healing causes plaque to build up where the arteries are damaged.

The buildup of plaque in the coronary arteries may start in childhood. Over time, plaque can narrow or completely block some of your coronary arteries. This reduces the flow of oxygen-rich blood to your heart muscle.

Plaque also can crack, which causes blood cells called platelets (PLATE-lets) to clump together and form blood clots at the site of the cracks. This narrows the arteries more and worsens angina or causes a heart attack.