A heart attack occurs when the muscle of the heart is damaged. The medical term for a heart attack is a myocardial infarction. All muscles in the human body require oxygen to function. A heart attack/myocardial infarction occurs when the heart muscle does not get enough oxygen. The coronary arteries are responsible for the delivery of oxygen to the heart muscle. When these arteries become severely blocked or narrowed, they restrict the flow of oxygen to the heart. The result may be a heart attack.

The symptoms of a heart attack vary, but are most commonly described as a squeezing, burning, tightness, fullness, or pressure across the chest. This discomfort may radiate to the shoulder, arms (especially the left), neck, jaw, teeth, earlobes, as well as the upper back between the shoulder blades. Numbness or tingling in the arms or hands may occur. Other symptoms include nausea and vomiting, sweating, palpitations, dizziness, and perhaps loss of consciousness.