

The plaque eventually breaks away and forms a clot. The interrupted blood flow can damage or destroy part of the heart muscle.



Common heart attack signs and symptoms include:

  • Nausea, indigestion, heartburn or abdominal pain
  • Shortness of breath
  • Cold sweat
  • Fatigue
  • Lightheadedness or sudden dizziness

Heart attack symptoms vary


Some heart attacks strike suddenly, but many people have warning signs and symptoms hours, days or weeks in advance. The earliest warning might be recurrent chest pain or pressure (angina) that's triggered by exertion and relieved by rest. Angina is caused by a temporary decrease in blood flow to the heart.

When to see a doctor






What to do if you see someone who might be having a heart attack

If you see someone who's unconscious and you believe is having a heart attack, first call for emergency medical help. Then check if the person is breathing and has a pulse. If the person isn't breathing or you don't find a pulse, only then should you begin CPR to keep blood flowing.





During a heart attack, one of these plaques can rupture and spill cholesterol and other substances into the bloodstream. A blood clot forms at the site of the rupture. If large enough, the clot can block the flow of blood through the coronary artery, starving the heart muscle of oxygen and nutrients (ischemia).

You might have a complete blockage or partial. A complete blockage means you've had an ST elevation myocardial infarction (STEMI). A partial blockage means you've had a non-ST elevation myocardial infarction (NSTEMI). Diagnostic steps and treatment might be different depending on which you've had.

Another cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle. Using tobacco and illicit drugs, such as cocaine, can cause a life-threatening spasm.

Risk factors


Heart attack risk factors include:

  • Tobacco. This includes smoking and long-term exposure to secondhand smoke.
  • High blood pressure. Over time, high blood pressure can damage arteries that feed your heart. High blood pressure that occurs with other conditions, such as obesity, high cholesterol or diabetes, increases your risk even more.
  • Diabetes. Not producing enough of a hormone secreted by your pancreas (insulin) or not responding to insulin properly causes your body's blood sugar levels to rise, increasing your risk of heart attack.
  • Metabolic syndrome. This occurs when you have obesity, high blood pressure and high blood sugar. Having metabolic syndrome makes you twice as likely to develop heart disease than if you don't have it.
  • Family history of heart attack. If your siblings, parents or grandparents have had early heart attacks (by age 55 for male relatives and by age 65 for female relatives), you might be at increased risk.
  • Lack of physical activity. Being inactive contributes to high blood cholesterol levels and obesity. People who exercise regularly have better cardiovascular fitness, including lower high blood pressure.
  • Stress. You might respond to stress in ways that can increase your risk of a heart attack.
  • An autoimmune condition. Having a condition such as rheumatoid arthritis or lupus can increase your risk of heart attack.



  • Heart failure. An attack might damage so much heart tissue that the remaining heart muscle can't pump enough blood out of your heart. Heart failure can be temporary, or it can be a chronic condition resulting from extensive and permanent damage to your heart.
  • Sudden cardiac arrest. Without warning, your heart stops due to an electrical disturbance that causes an arrhythmia. Heart attacks increase the risk of sudden cardiac arrest, which can be fatal without immediate treatment.




4 Ways to Prevent Heart Attack

The Mayo Clinic experience and patient stories


May 30, 2018
  1. Heart attack. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health-topics/heart-attack. Accessed March 9, 2018.
  2. Reeder GS, et al. Criteria for the diagnosis of acute myocardial infarction. https://www.uptodate.com/contents/search. Accessed March 9, 2018.
  3. About heart attacks. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartAttack/Heart-Attack_UCM_001092_SubHomePage.jsp. March 9, 2018.
  4. Acute coronary syndrome. American College of Cardiology. https://www.cardiosmart.org/Heart-Conditions/Acute-Coronary-Syndrome. Accessed March 13, 2018.
  5. 2014 Hands-Only CPR fact sheet. American Heart Association. http://www.heart.org/HEARTORG/CPRAndECC/HandsOnlyCPR/Hands-Only-CPR_UCM_440559_SubHomePage.jsp. Accessed March 13, 2018.
  6. Percutaneous coronary intervention. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health-topics/percutaneous-coronary-intervention. Accessed March 13, 2018.
  7. Heart attack or sudden cardiac arrest: How are they different? American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartAttack/AboutHeartAttacks/Heart-Attack-or-Sudden-Cardiac-Arrest-How-Are-They-Different_UCM_440804_Article.jsp#.WqfnPoJG3yw. Accessed March 13, 2018.
  8. Non-invasive tests and procedures. American Heart Association. http://www.heart.org/HEARTORG/Conditions/HeartAttack/DiagnosingaHeartAttack/Non-Invasive-Tests-and-Procedures_UCM_303930_Article.jsp#.Wqfp4YJG3yw. Accessed March 13, 2018.
  9. Wilson PW, et al. Prognosis after myocardial infarction. https://www.uptodate.com/contents/search. Accessed March 9, 2018.