Heart Attack

What is a heart attack?

A heart attack occurs when blood flow to the heart is blocked. Without blood and the oxygen it carries, part of the heart starts to die. A heart attack doesn't have to be deadly. Quick treatment can restore blood flow to the heart and save your life.

Your doctor might call a heart attack a myocardial infarction, or MI. 

What causes a heart attack?

Heart attacks happen when blood flow to the heart is blocked. This usually occurs because fatty deposits called plaque have built up inside the coronary arteries, which supply blood to the heart. If a plaque breaks open, the body tries to fix it by forming a clot around it. The clot can block the artery, preventing the flow of blood and oxygen to the heart. See a picture of how plaque causes a heart attack.

This process of plaque buildup in the coronary arteries is called coronary artery disease, or CAD. In many people, plaque begins to form in childhood and gradually builds up over a lifetime. Plaque deposits may limit blood flow to the heart and cause angina. But too often, a heart attack is the first sign of CAD.

Things like intense exercise, sudden strong emotion, or illegal drug use can trigger a heart attack. But in many cases, there is no clear reason why heart attacks occur when they do.

What are the symptoms?

The most common symptom of a heart attack is severe chest pain.

  • Many people describe the pain as discomfort, pressure, squeezing, or heaviness in the chest.
  • People often put their fist to their chest when they describe the pain.
  • The pain may spread down the left shoulder and arm and to other areas, such as the back, jaw, neck, or right arm.

Many people also have at least one other symptom, such as:

  • Pain in the upper belly, often mistaken for heartburn.
  • Sweating.
  • Nausea and vomiting.
  • Trouble breathing.
  • A feeling that their heart is racing or pounding (palpitations).
  • Feeling weak or very tired.
  • Feeling dizzy or fainting.

Not everyone has the classic symptom of severe chest pain during a heart attack. Women, older adults, and people with diabetes are less likely to have severe chest pain and more likely to have shortness of breath, dizziness, weakness or fainting, and belly pain. 

What should you do if you think you are having a heart attack?

If you have symptoms of a heart attack, act fast. Each year, 4 out of 10 people who have a heart attack die, many of them before they reach the hospital.  Quick treatment could save your life.

The best choice is to go to the hospital in an ambulance. The paramedics can begin lifesaving treatments even before you arrive at the hospital. If you cannot reach emergency services, have someone drive you to the hospital right away. Do not drive yourself unless you have absolutely no other choice. 

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