A healthy heart is a big, strong muscle.

Its job is to pump blood throughout the body.

Coronary arteries help the heart by supplying it with oxygen-rich blood.

But over time, cholesterol and fats can build up in our arteries.

This buildup is called plaque.

If plaque breaks open, a blood clot can form.

And if that clot blocks the artery, your heart won't get enough blood and oxygen, which means that cells in your heart muscle may die.

When that happens, it’s called a heart attack.

There are other less common reasons that oxygen-rich blood might be blocked.

For example, a spasm or a tear in the artery can block blood flow.

Now, a heart attack doesn't have to be deadly.

Quick treatment can get the blood flowing to the heart, reduce the damage to the heart, and save a life.