The heart pumps blood which carries oxygen and nutrition, to all parts of the body.
The heart has to supply blood to its own muscle too and this it does through vessels called coronary arteries. Blockage of one or more of these arteries starves the heart of oxygen. If the blockage is slight only pain results; if severe, the portion of the muscle that is starved, dies. We call this a heart attack.
How can an artery get blocked?
An artery can get blocked due to build-up of fatty and other materials on the inner lining of the artery causing it to narrow and thicken. Sometimes the fatty deposit might completely close up an artery. Also, when blood is flowing through an artery that has become narrow, the friction between the blood and the walls could cause a clot to form. A clot can completely stop the flow of blood in an artery. In some cases the effects of the blockage can be so severe that the heart stops beating altogether. We call this a cardiac arrest.
There has been great progress in the diagnosis and control of heart diseases in recent years and today many people live after heart attacks.