Every year about 805,000 Americans have a heart attack.
The heart pumps oxygen-rich blood to the rest of the body through an intricate network of arteries. However, the arteries around your heart can get blocked, usually by a blood clot and less often because of severe spasms and dissection. When this happens, blood flow is slowed or blocked.
The classic image of a person having a heart attack is one of a person clutching their chest, complaining of crushing chest pain or an elephant sitting on their chest. However, in real life, the symptoms can be more subtle.