Heart Health Heart Disease Heart Attack Heart Attack Guide Heart Attack Guide Symptoms Causes Diagnosis Treatment Prevention Causes and Risk Factors of a Heart Attack By Richard N. Fogoros, MD Richard N. Fogoros, MD Facebook LinkedIn Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology. Learn about our editorial process Updated on November 27, 2021 Medically reviewed by Richard N. Fogoros, MD Medically reviewed by Richard N. Fogoros, MD Facebook LinkedIn Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Common Causes Genetics Non-Controllable Risk Factors Lifestyle Risk Factors Frequently Asked Questions Next in Heart Attack Guide How a Heart Attack Is Diagnosed A heart attack (myocardial infarction, or MI) occurs when a portion of the heart muscle is deprived of blood and becomes damaged. In most cases, a heart attack is a sudden event that occurs when an atherosclerotic plaque—a build-up of lipids and other substances in the artery—in the wall of a coronary artery ruptures (breaks off) and causes a blood clot to form, blocking a smaller artery in the heart muscle. This often occurs due to longstanding coronary artery disease (CAD). There are other conditions that can lead to myocardial infarction as well. Patrick Heagney / Getty Images Common Causes A heart attack is necrosis (death) of the heart muscle. This occurs due to insufficient blood supply. A thrombus (localized blood clot) due to a ruptured coronary artery plaque is the most common reason for heart muscle necrosis, and there are several other causes as well. A heart attack usually causes angina, which feels like chest pressure, tightness, or pain. It usually also causes severe shortness of breath. Acute Coronary Syndrome When a coronary artery plaque ruptures, it can cause the formation of a blood clot (localized thrombosis) that impedes blood flow to the heart. This is called acute coronary syndrome, or ACS. The consequences of ACS depend on the extent to which the artery is blocked by the new blood clot. Acute coronary syndrome associated with typical CAD is, by far, the most common cause of myocardial infarction. When a blood clot dissolves quickly, before the heart becomes damaged, the episode is referred to as unstable angina. If the blockage is severe enough to cause death of a portion of the heart muscle—this is a heart attack. The Two Types of Heart Attack Non-ST segment myocardial infarction (NSTEMI), in which only some of the heart muscle is damaged ST-segment elevation myocardial infarction (STEMI), in which nearly all of the muscle supplied by the occluded artery dies Coronary Artery Spasm Also known as Prinzmetal angina, vasospastic angina, or variant angina, coronary artery spasm is exactly what it sounds like: a sudden involuntary contraction of a coronary artery. Most people with coronary artery spasm will have brief episodes of angina, rather than an actual myocardial infarction. A severe and prolonged episode of coronary artery spasm can result in permanent damage to a portion of the heart muscle. Microvascular Angina Very rarely, a condition called microvascular angina (or cardiac syndrome X) will lead to a heart attack. Microvascular angina is caused by endothelial dysfunction, in which the smaller coronary arteries don't dilate (widen) normally, creating an obstruction to blood flow. People with microvascular angina will have normal-looking coronary arteries during cardiac catheterization, a test used to evaluate and treat heart conditions. Stress Cardiomyopathy Nicknamed "broken heart syndrome," stress cardiomyopathy is sudden, severe heart failure triggered by extreme emotional trauma or physical stress. With appropriate treatment, most people who have this condition survive and have recovery of heart function. But in some cases, part of the heart muscle can be permanently damaged. The cause of this condition is unknown, but it is thought to be related to endothelial dysfunction, similar to microvascular angina. What Is Broken Heart Syndrome? Viral Myocarditis Viral myocarditis is a viral infection that directly affects the heart muscle. Viral myocarditis is not typically considered a cause of myocardial infarction, though it often does cause permanent heart muscle damage. It is believed to produce extensive localized inflammation in the cardiac muscle and interruption of the local blood supply. Blood Clotting Disorders Certain disorders of the blood-clotting pathway, such as Factor V Leiden deficiency, predispose to abnormal blood clotting. People with such conditions can develop acute thrombosis of a coronary artery even without underlying CAD, and thus, can experience myocardial infarctions. Coronary Artery Embolism A myocardial infarction can occur if a blood clot, usually originating within the heart, embolizes (breaks free) and becomes lodged in a coronary artery, interrupting the blood supply to part of the heart muscle. Certain medical conditions increase the risk of blood clot embolization, including atrial fibrillation, dilated cardiomyopathy, and the presence of an artificial heart valve. In these cases, blood thinners are often prescribed to help prevent this from happening. How Blood Clots Are Treated Genetics Genetic factors that may be involved in a person's risk of heart attack can be directly linked to a particular cardiovascular condition or to an elevated risk of a trait associated with an increased heart disease risk, such as a tendency to be overweight, have abnormal blood lipid levels, or develop type 2 diabetes or hypertension. While some specific genes and hereditary patterns have been identified, there are many unknowns when it comes to genetic risk factors for heart attack. For example, it's known that, in some families, the elevated risk is clearly related to an identifiable inherited disorder such as familial hypercholesterolemia. However, although researchers have been able to identify certain gene variants associated with diseases that ultimately lead to heart failure, such as hypertrophic cardiomyopathy, having the gene variant does not necessarily mean that you will develop this condition. Non-Controllable Risk Factors Aside from genetics, there are a handful of other uncontrollable factors that can increase the possibility a person could have a heart attack: Age: The risk increases for men who are 55 or older and women who are 65 and olderChronic kidney diseaseType 1 diabetesFor women, being post-menopausal or having had an ovary removal Lifestyle Risk Factors Whether you have a genetic predisposition to heart attacks or not, your risks can often be reduced with healthy lifestyle strategies. Keep in mind that lifestyle factors can put anyone, regardless of family history, at an increased risk of a heart attack. The most important ones include: Obesity, especially if most excess weight is located in the abdominal area Inactivity—people who engage in regular exercise have a decreased risk of heart problems High blood levels of low-density lipoprotein (LDL) cholesterol or triglycerides (fats) Low levels of high-density lipoprotein (HDL) cholesterol Hypertension (high blood pressure) Type 2 diabetes and insulin resistance Smoking and other types of tobacco use Smoking is the chief cause of heart attacks in people under 40. A Word From Verywell Most heart attacks are caused by the dislodging of an atherosclerotic plaque in a coronary artery, but there are several other, much less common causes as well. More important to know: There are many things you can do to prevent this from happening—eating a healthy diet, getting regular exercise, and not smoking (or kicking the habit if you already do). These measures may help mitigate your risk even if heart problems run in your family, and they'll help prevent you from developing other chronic conditions as well. Frequently Asked Questions What are the signs of a silent heart attack? A silent heart attack is one that doesn't cause dramatic symptoms—if any at all.If they're present, symptoms may include:Pressure, discomfort, or a feeling of fullness in the chest (rather than outright pain)Discomfort in the arms (either or both), back, neck, jaw, or stomachTrouble breathingDizziness or lightheadednessNauseaCold sweats Can being stressed cause a heart attack? Psychosocial factors, including chronic stress, are linked to heart disease, which contributes/or can lead to heart attacks.Sudden stress, such as the loss of a loved one, can cause what's called takotsubo cardiomyopathy, also known as broken heart syndrome. When it first occurs, takotsubo cardiomyopathy can feel like a heart attack. Can an otherwise healthy person have a heart attack? Yes. It's possible to maintain a heart-healthy lifestyle and still have a heart attack. This is most likely to happen if you have a family history of cardiac problems. If heart disease runs in your family, tell your primary care physician so they can monitor your cardiac health. How a Heart Attack Is Diagnosed 19 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. The American Heart Association. Understand your risk for excessive blood clotting. Harvard Health Publishing. Heart attack (myocardial infarction). Baylor Scott & White Heart and Vascular Hospital. Angina pectoris, unstable. NIH: National Center for Advancing Translational Sciences. Prinzmetal's variant angina. American Heart Association. Microvascular angina. Bugiardini R, Badimon L, Collins P, et al. Angina, "normal" coronary angiography, and vascular dysfunction: risk assessment strategies. PLoS Med. 2007;4(2):e12. doi:10.1371/journal.pmed.0040012 Johns Hopkins Medicine. Stress cardiomyopathy symptoms and diagnosis. Kassas I, Tran K-V, Fitzgibbons T, et al. Endothelial Dysfunction and Inflammation in Stress Cardiomyopathy. Circulation. 2018;134(1). Harvard Health Publishing. Myocarditis. Dowaidar M, Settin A. Risk of myocardial infarction related to factor V Leiden mutation: a meta-analysis. Genet Test Mol Biomarkers. 2010;14(4):493-8. doi:10.1089/gtmb.2010.0017 American Heart Association. About heart attacks. Nesheiwat Z, Goyal A, Jagtap M. Atrial Fibrillation (A Fib). In: StatPearls [Internet]. Centers for Disease Control and Prevention. Know your risk for heart disease. Singh A, Gupta A, Collins BL, et al. Familial hypercholesterolemia among young adults with myocardial infarction. J Am Coll Cardiol. 2019;73(19):2439-2450. doi:10.1016/j.jacc.2019.02.059 NIH US National Library of Medicine Genetics Home Reference. Familial hypertrophic cardiomyopathy. American Heart Association. Understand your risks to prevent a heart attack. American Heart Association. Lifestyle changes for heart attack prevention. Penn Medicine. 4 Silent Heart Attack Signs. The American Institute of Stress. Stress can cause a cardiac event that resembles a heart attack. Additional Reading Crea F, Liuzzo G. Pathogenesis Of Acute Coronary Syndromes. J Am Coll Cardiol. 2013 Jan 8;61(1):1-11. doi: 10.1016/j.jacc.2012.07.064 Lindahl B, Baron T, Erlinge D, et al. Medical Therapy for Secondary Prevention and Long-Term Outcome in Patients With Myocardial Infarction With Nonobstructive Coronary Artery Disease. Circulation 2017 Apr 18;135(16):1481-1489. doi:10.1161/CIRCULATIONAHA.116.026336 Niccoli G, Scalone G, Crea F. Acute Myocardial Infarction With No Obstructive Coronary Atherosclerosis: Mechanisms And Management. Eur Heart J. 2015 Feb 21;36(8):475-81. doi:10.1093/eurheartj/ehu469. By Richard N. Fogoros, MD Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit