A myocardial infarction is the medical term for a heart attack. It happens when blood flow to part of the heart muscle gets blocked, usually by a clot in one of the heart's arteries. Without blood bringing oxygen, that section of heart muscle starts to die, which can be extremely dangerous.

Doctors use this precise term, but most people just say “heart attack.”

Heart attacks are medical emergencies. Someone having one might feel crushing chest pain, shortness of breath, or pain spreading to their arm or jaw. Quick treatment can save lives by reopening the blocked artery before too much heart muscle is damaged. This is why you often hear that every minute counts when someone shows heart attack symptoms.

While heart attacks mostly affect older adults, understanding them matters because knowing the warning signs can help you get help for someone who needs it. Paramedics and emergency room doctors are specially trained to treat myocardial infarctions quickly, using medicines or procedures to restore blood flow to the heart.