Can you clench your fist 100,000 times a day? Take 100,000 steps? Click a computer mouse 100,000 times in 24 hours?

Welcome to the life of a heart.

A powerful muscle about the size of a fist, the heart beats about 100,000 times a day, pumping blood through the body. In order to work, the heart needs oxygen and nutrients carried by blood.

Sticky, fatty material carried in the blood called plaque, which includes cholesterol, can build up in the coronary arteries that carry blood to the heart. These blood vessels can become clogged, like water pipes or a kitchen drain can become blocked with sludge. The process is called atherosclerosis and can start to develop in childhood. (Athero is Greek for paste, sclerosis means hardness.)

As plaque ages, it can harden and crack. A blood clot can form at the crack like a scab. This blood clot, called a thrombus, can also block the artery, shutting off the blood supply to the heart.

As the blood flow decreases, the heart doesn’t get the oxygen and nutrients it needs. When the arteries are blocked with atherosclerotic plaque and harden and narrow, it’s called coronary artery disease. It's one of the most common forms of heart disease and one of the leading causes of death in the country.

Coronary artery disease can lead to a heart attack by shutting off the heart's supply of blood. A heart attack, or myocardial infarction, means part of the heart muscle has died.