A heart attack occurs when blood flow to the heart is blocked. However, the main underlying causes of a heart attack are more complex.

To understand how a heart attack occurs, it helps to know how the heart works. Basically, your heart is a muscle—an extremely important one. When working properly, the heart pumps oxygen and nutrients throughout the body through a series of blood vessels. The heart itself is no different than the rest of the body; it needs to receive t blood through an artery to continue doing its job.

There are three main vessels that provide oxygen to the heart. When one of those blood vessels is blocked by a ruptured plaque, a clot forms on the exposed plaque and slows or blocks blood flow to the heart. When a vessel is blocked altogether, blood can no longer reach the heart, causing parts of the muscle to become damaged and die.

Coronary Artery Disease

A heart attack is almost always triggered by a piece of plaque that cracks or tears, causing blood clots to form around the tear and disrupt blood flow through an artery. In the case of most heart attacks, coronary artery disease is to blame. Coronary artery disease is a condition in which plaque builds up on the walls of the arteries, reducing blood flow to the heart. Plaque is made up of fatty substances in the blood, like cholesterol, as well as other cells and proteins that surround the plaque. Certain types of plaque have a tendency to rupture, leading to heart attack.

The primary causes of coronary artery disease Include:

  • smoking
  • high blood pressure
  • high amounts of fats, cholesterol and sugar in the blood

These factors actually damage the inside of the coronary arteries, leaving them vulnerable to the development of plaques at the site of damage.

A heart attack can also be caused by a temporary contraction or spasm of the artery. Though rare, these contractions can cause the artery to narrow or close altogether.